Telegram (software)

Telegram was launched in 2013 by the brothers Nikolai and Pavel Durov. Previously, the pair founded the Russian social network VK, which they left in 2014, saying it had been taken over by the government.{{cite news |url=http://articles.economictimes.indiatimes.com/2014-04-22/news/49318882_1_social-network-vkontakte-pavel-durov-founder-mark-zuckerberg |title=Pavel Durov left Russia after being pushed out |date=22 April 2014 |access-date=23 April 2014 |url-status=dead |archive-url=https://web.archive.org/web/20140424024304/http://articles.economictimes.indiatimes.com/2014-04-22/news/49318882_1_social-network-vkontakte-pavel-durov-founder-mark-zuckerberg |archive-date=24 April 2014 |publisher=Agence France-Presse |via=Economic Times }} Pavel sold his remaining stake in VK and left Russia after resisting government pressure. Nikolai created the MTProto protocol that is the basis for the messenger, while Pavel provided financial support and infrastructure through his Digital Fortress fund.{{cite web|url=https://techcrunch.com/2013/10/27/meet-telegram-a-secure-messaging-app-from-the-founders-of-vk-russias-largest-social-network/|title=Meet Telegram, A Secure Messaging App From The Founders Of VK, Russia's Largest Social Network|last=Shu|first=Catherine|date=27 October 2013|website=TechCrunch|access-date=18 March 2016|archive-date=26 November 2015|archive-url=https://web.archive.org/web/20151126020419/http://techcrunch.com/2013/10/27/meet-telegram-a-secure-messaging-app-from-the-founders-of-vk-russias-largest-social-network/|url-status=live}} Telegram Messenger states that its end goal is not to bring profit,{{cite web |url=https://telegram.org/faq#q-how-are-you-going-to-make-money-out-of-this |title=Telegram F.A.Q |url-status=live |archive-url=https://web.archive.org/web/20140209082001/https://telegram.org/faq#q-how-are-you-going-to-make-money-out-of-this |archive-date=9 February 2014 |quote=...making profits will never be an end-goal for Telegram.}}{{cite news |url=https://www.theverge.com/2014/2/25/5445864/telegram-messenger-hottest-app-in-the-world |title=Why Telegram has become the hottest messaging app in the world |url-status=live |archive-url=https://web.archive.org/web/20160313050911/http://www.theverge.com/2014/2/25/5445864/telegram-messenger-hottest-app-in-the-world |archive-date=13 March 2016 |work=The Verge |access-date=25 February 2014 |quote=Telegram operates as a non-profit organization, and doesn’t plan to charge for its services.}} but it is not structured as a non-profit organization.{{cite news|url=https://www.washingtonpost.com/news/the-intersect/wp/2015/11/23/the-secret-american-origins-of-telegram-the-encrypted-messaging-app-favored-by-the-islamic-state/|title=The secret American origins of Telegram, the encrypted messaging app favored by the Islamic State|last1=Dewey|first1=Caitlin|date=23 November 2015|access-date=31 March 2018|newspaper=The Washington Post|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512135529/https://www.washingtonpost.com/news/the-intersect/wp/2015/11/23/the-secret-american-origins-of-telegram-the-encrypted-messaging-app-favored-by-the-islamic-state/|url-status=live}}

Telegram is registered as a company in the British Virgin Islands and as an LLC in Dubai.{{cite web|title = Telegram Messenger on the App Store|url = https://apps.apple.com/app/telegram-messenger/id686449807|website = App Store|access-date = 19 November 2015|archive-date = 19 May 2019|archive-url = https://web.archive.org/web/20190519201602/https://itunes.apple.com/app/telegram-messenger/id686449807|url-status = live}}[https://www.dnb.com/business-directory/company-profiles.telegram_fz_llc.adcbb6d4f706fd666c04a7b5c9178b02.html Telegram FZ LLC – Dun & Bradstreet] It does not disclose where it rents offices or which legal entities it uses to rent them, citing the need to "shelter the team from unnecessary influence" and protect users from governmental data requests.{{Cite news|title = Lunch with the FT: Pavel Durov|url = http://www.ft.com/cms/s/0/21c5c7f2-20b1-11e5-ab0f-6bb9974f25d0.html|newspaper = Financial Times|access-date = 19 November 2015|first = John|last = Thornhill|date = 3 July 2015|archive-date = 19 September 2016|archive-url = https://web.archive.org/web/20160919235800/http://www.ft.com/cms/s/0/21c5c7f2-20b1-11e5-ab0f-6bb9974f25d0.html|url-status = live}} After Pavel Durov left Russia in 2014, he was said to be moving from country to country with a small group of computer programmers consisting of 15 core members.{{Cite news|title = Once Celebrated in Russia, the Programmer Pavel Durov Chooses Exile|url = https://www.nytimes.com/2014/12/03/technology/once-celebrated-in-russia-programmer-pavel-durov-chooses-exile.html|newspaper = The New York Times|date = 2 December 2014|access-date = 19 November 2015|first = Danny|last = Hakim|archive-date = 6 September 2015|archive-url = https://web.archive.org/web/20150906024632/http://www.nytimes.com/2014/12/03/technology/once-celebrated-in-russia-programmer-pavel-durov-chooses-exile.html|url-status = live}}{{cite news|url=https://www.reuters.com/article/us-telecoms-mobileworld-telegram-idUSKCN0VW2CM|title=Telegram app free-speech advocate no stranger to Apple-FBI woes|newspaper=Reuters|date=23 February 2016|via=www.reuters.com|access-date=12 August 2019|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512140540/https://www.reuters.com/article/us-telecoms-mobileworld-telegram-idUSKCN0VW2CM|url-status=live|last1=Auchard|first1=Eric}}

While a former employee of VK said that Telegram had employees in Saint Petersburg, Pavel said the Telegram team made Berlin, Germany, its headquarters in 2014,{{cite web|url = https://www.theverge.com/2014/10/6/6926205/surveillance-drives-south-koreans-to-encrypted-messaging-apps|title = Surveillance drives South Koreans to encrypted messaging apps|date = 6 October 2014|website = The Verge|access-date = 19 November 2015|first = Russell|last = Brandom|archive-date = 6 November 2015|archive-url = https://web.archive.org/web/20151106162327/http://www.theverge.com/2014/10/6/6926205/surveillance-drives-south-koreans-to-encrypted-messaging-apps|url-status = live}} but failed to obtain German residence permits for everyone on the team and moved to other jurisdictions in early 2015.{{cite web|last1=Turton|first1=William|title=What isn't Telegram saying about its connections to the Kremlin?|url=https://theoutline.com/post/2348/what-isn-t-telegram-saying-about-its-connections-to-the-kremlin|website=The Outline|access-date=11 October 2017|date=29 September 2017|archive-date=18 May 2019|archive-url=https://web.archive.org/web/20190518221134/https://theoutline.com/post/2348/what-isn-t-telegram-saying-about-its-connections-to-the-kremlin|url-status=live}} Since 2017, the company has been based in Dubai.{{cite news |last1=Descalsota |first1=Marielle |title=Meet Pavel Durov, the tech billionaire who founded Telegram, fled from Moscow 15 years ago after defying the Kremlin, and has a penchant for posting half-naked selfies on Instagram |url=https://www.businessinsider.com/pavel-durov-telegram-billionaire-russia-instagram-wealth-founder-dubai-lifestyle-2022-3 |access-date=1 May 2022 |work=Business Insider |date=28 March 2022}} Its data centers are spread across a complex corporate structure of shell companies in various jurisdictions to avoid compliance with government subpoenas.{{Cite news |last=Hakim |first=Danny |date=2 December 2014 |title=Once Celebrated in Russia, the Programmer Pavel Durov Chooses Exile |language=en-US |work=The New York Times |url=https://www.nytimes.com/2014/12/03/technology/once-celebrated-in-russia-programmer-pavel-durov-chooses-exile.html |access-date=19 August 2022 |issn=0362-4331}}{{Cite web |last=Newton |first=Casey |date=26 August 2024 |title=How Telegram played itself |url=https://www.platformer.news/telegram-durov-arrest-france-explainer/ |access-date=28 August 2024 |website=Platformer |language=en}} The company says this is done "to protect the data that is not covered by end-to-end encryption". Telegram's FAQ page says it does not process any requests related to illegal content in chats and group chats, and that "to this day, we have disclosed 0 bytes of user messages to third parties, including governments". However, according to Pavel, Telegram has disclosed data for 203 legal requests from the Brazilian government from Q1 to Q3 of 2024, and a total of 6,992 legal requests from India, its largest market, during the same period.{{Cite web |title=Du Rove's Channel |url=https://t.me/durov/346 |access-date=5 October 2024 |website=Telegram}} Users can check how many legal requests from their country have been processed by Telegram using the official transparency bot.

In October 2013, Telegram announced that it had 100,000 daily active users.

On 24 March 2014, Telegram announced that it had reached 35 million monthly users and 15 million daily active users.{{cite web|url=https://techcrunch.com/2014/03/24/telegram-hits-35m-monthly-users-15m-daily-with-8b-messages-received-over-30-days/|publisher=TechCrunch|title=Telegram Hits 35M Monthly Users, 15M Daily With 8B Messages Received Over 30 Days|date=24 March 2014|access-date=25 June 2017|archive-date=24 November 2015|archive-url=https://web.archive.org/web/20151124123902/http://techcrunch.com/2014/03/24/telegram-hits-35m-monthly-users-15m-daily-with-8b-messages-received-over-30-days/|url-status=live}} In October 2014, South Korean government surveillance plans drove many of its citizens to switch to Telegram from the Korean app KakaoTalk. In December 2014, Telegram announced that it had 50 million active users, generating 1 billion daily messages, and that it had 1 million new users signing up on its service every week,{{cite web|url=https://telegram.org/blog/billion|publisher=Telegram|title=Telegram Reaches 1 Billion Daily Messages|date=8 December 2014|access-date=8 December 2014|archive-date=24 July 2019|archive-url=https://web.archive.org/web/20190724110557/https://telegram.org/blog/billion|url-status=live}} traffic doubled in five months with 2 billion daily messages.{{cite web|url=https://telegram.org/blog/2-billion|publisher=Telegram|title=Telegram Hits 2 Billion Messages Sent Daily|date=13 May 2015|access-date=31 July 2015|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512141610/https://telegram.org/blog/2-billion|url-status=live}} In September 2015, Telegram announced that the app had 60 million active users and delivered 12 billion daily messages.{{cite web|url = https://techcrunch.com/2015/09/21/telegram-now-seeing-12bn-daily-messages-up-from-1m-in-february/|title = Telegram Now Seeing 12BN Daily Messages, up From 1BN in February|date = 21 September 2015|access-date = 19 November 2015|website = Techcrunch|last = Lomas|first = Natasha|archive-date = 27 November 2015|archive-url = https://web.archive.org/web/20151127133011/http://techcrunch.com/2015/09/21/telegram-now-seeing-12bn-daily-messages-up-from-1m-in-february/|url-status = live}}

In February 2016, Telegram announced that it had 100 million monthly active users, with 350,000 new users signing up every day, delivering 15 billion messages daily.{{cite web|title = Encrypted Messaging App Telegram Hits 100M Monthly Active Users, 350k New Users Each Day|url = https://techcrunch.com/2016/02/23/encrypted-messaging-app-telegram-hits-100m-monthly-active-users-350k-new-users-each-day/|website = TechCrunch|access-date = 23 February 2016|first = Matt|last = Burns|date = 23 February 2016|archive-date = 9 May 2019|archive-url = https://web.archive.org/web/20190509222256/https://techcrunch.com/2016/02/23/encrypted-messaging-app-telegram-hits-100m-monthly-active-users-350k-new-users-each-day/|url-status = live}} In December 2017, Telegram reached 180 million monthly active users.{{cite news |title = This $5 Billion Encrypted App Isn't for Sale at Any Price |url = https://www.bloomberg.com/news/articles/2017-12-12/cryptic-russian-crusader-says-his-5-billion-app-can-t-be-bought |newspaper = Bloomberg |date = 12 December 2017 |access-date = 22 December 2017 |archive-date = 20 May 2019 |archive-url = https://web.archive.org/web/20190520015516/https://www.bloomberg.com/news/articles/2017-12-12/cryptic-russian-crusader-says-his-5-billion-app-can-t-be-bought |url-status = live }} By March 2018, that number had doubled, with Telegram reaching 200 million monthly active users.{{cite web|url=https://telegram.org/blog/200-million|title=200,000,000 Monthly Active Users|date=22 March 2018|website=Telegram|access-date=22 March 2018|archive-date=23 September 2018|archive-url=https://web.archive.org/web/20180923104039/https://telegram.org/blog/200-million|url-status=live}}

On 14 March 2019, Pavel said that "3 million new users signed up for Telegram within the last 24 hours."{{cite web |last1=Lomas |first1=Natasha |title=Telegram gets 3M new signups during Facebook apps' outage |url=https://techcrunch.com/2019/03/14/telegram-gets-3m-new-signups-during-facebook-apps-outage/ |website=TechCrunch |date=14 March 2019 |access-date=14 March 2019 |archive-date=2 May 2019 |archive-url=https://web.archive.org/web/20190502055020/https://techcrunch.com/2019/03/14/telegram-gets-3m-new-signups-during-facebook-apps-outage/ |url-status=live }} He did not specify what prompted this flood of new sign-ups, but the period matched a prolonged technical outage experienced by Facebook and its family of apps, including Instagram.{{cite web |last1=Shieber |first1=Jonathan |title=Update: Facebook, Instagram and Messenger were down for many users |url=https://techcrunch.com/2019/03/13/facebook-instagram-and-messenger-are-down-for-some-users/ |website=TechCrunch |date=13 March 2019 |access-date=14 March 2019 |archive-date=2 May 2019 |archive-url=https://web.archive.org/web/20190502055019/https://techcrunch.com/2019/03/13/facebook-instagram-and-messenger-are-down-for-some-users/ |url-status=live }} According to the US Securities and Exchange Commission, as of October 2019, Telegram had 300 million monthly active users worldwide.{{cite web |url=https://www.sec.gov/litigation/complaints/2019/comp-pr2019-212.pdf |title=SECURITIES AND EXCHANGE COMMISSION, ::Plaintiff, :19 Civ. 9439(PKC):-against -:ECF Case:TELEGRAM GROUPINC.andTON ISSUERINC. |date=11 October 2019 |website=The US Securities and Exchange Commission |access-date=17 October 2019 |archive-date=12 November 2020 |archive-url=https://web.archive.org/web/20201112015601/https://www.sec.gov/litigation/complaints/2019/comp-pr2019-212.pdf |url-status=live }}

On 24 April 2020, Telegram announced that it had reached 400 million monthly active users.{{Cite web |title=Telegram hits 500M monthly active users |url=https://t.me/durov/147/ |url-status=live |archive-url=https://web.archive.org/web/20210611161236/https://t.me/durov/147 |archive-date=11 June 2021 |access-date=12 January 2021 |website=Telegram |language=en-US}}

On 8 January 2021, Pavel announced in a blog post that Telegram had reached "about 500 million" monthly active users.{{cite web |url=https://www.thehindubusinessline.com/news/respect-your-users-telegram-founder-slams-facebook/article33535421.ece |title="Respect your users": Telegram founder Pavel Durov slams Facebook |date=9 January 2021 |website=The Hindu Business Line |access-date=10 January 2021 |archive-date=9 January 2021 |archive-url=https://web.archive.org/web/20210109093123/https://www.thehindubusinessline.com/news/respect-your-users-telegram-founder-slams-facebook/article33535421.ece |url-status=live }} In August, TechCrunch reported that India was Telegram's largest market, with a 22% share of total installs coming from the region.{{cite web |url=https://techcrunch.com/2021/08/30/telegram-tops-1-billion-downloads/ |title=Telegram tops 1 billion downloads |date=30 August 2021 |website=TechCrunch |access-date=1 May 2022}} Telegram then gained over 70 million new users as a result of an outage which affected Facebook and its affiliates on 5 October 2021.{{Cite web|last=Porter|first=Jon|date=6 October 2021|title=Telegram gains 70M new users in just one day after Facebook outage|url=https://www.theverge.com/2021/10/6/22712191/telegram-70-million-new-users-facebook-outage-surge-whatsapp|access-date=6 October 2021|website=The Verge|language=en-US|archive-date=6 October 2021|archive-url=https://web.archive.org/web/20211006143403/https://www.theverge.com/2021/10/6/22712191/telegram-70-million-new-users-facebook-outage-surge-whatsapp|url-status=live}}

On 19 June 2022, Telegram announced that it had reached 700 million monthly active users.{{cite web |last1=Roth |first1=Emma |date=20 June 2022 |title=Telegram's Premium subscription is here and it costs $4.99 / month |url=https://www.theverge.com/2022/6/19/23174976/telegram-premium-subscription-4-99-month-bigger-uploads-faster-downloads |access-date=20 June 2022 |website=The Verge}}{{Cite web |date=21 June 2022 |title=700 Million Users and Telegram Premium |url=https://telegram.org/blog/700-million-and-premium |access-date=8 July 2022 |website=Telegram}}

In July 2023, Telegram surpassed 800 million monthly active users,{{cite web |last1=Singh |first1=Manish |date=18 July 2023 |title=Telegram raises $210 million through bond sales |url=https://techcrunch.com/2023/07/18/telegram-raises-210-million-through-bond-sales/ |access-date=2 August 2023 |website=TechCrunch}} later reaching 900 million in March 2024{{Cite news |last1=Murphy |first1=Hannah |date=11 March 2024 |title=Telegram hits 900mn users and nears profitability as founder considers IPO |url=https://www.ft.com/content/8d6ceb0d-4cdb-4165-bdfa-4b95b3e07b2a |url-access=subscription |archive-url=https://archive.today/20240312072805/https://www.ft.com/content/8d6ceb0d-4cdb-4165-bdfa-4b95b3e07b2a |archive-date=12 March 2024 |access-date=12 March 2024 |website=Financial Times}} and 950 million in July 2024.{{Cite web |last=Mehta |first=Ivan |date=23 July 2024 |title=Telegram's user base climbs to 950M, plans to launch app store |url=https://techcrunch.com/2024/07/23/telegrams-userbase-climbs-to-950m-plans-to-launch-app-store/ |access-date=23 December 2024 |website=TechCrunch |language=en-US}} In March 2025, Pavel Durov announced that Telegram surpassed 1 billion monthly active users.{{Cite web |title=Pavel Durov |url=https://t.me/durov/404 |access-date=2025-06-14 |website=Telegram}}{{Cite web |last=Mehta |first=Ivan |date=2025-03-19 |title=Telegram founder Pavel Durov says app now has 1B users, calls WhatsApp a 'cheap, watered down imitation' |url=https://techcrunch.com/2025/03/19/telegram-founder-pavel-durov-says-app-now-has-1b-users-calls-whatsapp-a-cheap-watered-down-imitation/ |access-date=2025-06-14 |website=TechCrunch |language=en-US}}

File:Telegram-account-self-destruction.png

To start using Telegram, a user must sign-up with their phone number or an anonymous +888 number purchased from the Fragment blockchain platform.{{cite web |last=Lopez |first=Miguel |date=30 January 2014 |title=Configurando Telegram en el iPhone, en la web y en el Mac |trans-title=Configuring Telegram in the Apple iPhone, the Web and the Mac |url=http://www.applesfera.com/aplicaciones-ios-1/configurando-telegram-en-el-iphone-en-la-web-y-en-el-mac |url-status=live |archive-url=https://web.archive.org/web/20190807133141/https://www.applesfera.com/aplicaciones-ios-1/configurando-telegram-en-el-iphone-en-la-web-y-en-el-mac |archive-date=7 August 2019 |access-date=4 December 2014 |publisher=Applesfera |language=es}}{{Cite web |last=Mehta |first=Ivan |date=7 December 2022 |title=Telegram is auctioning phone numbers to let users sign up to the service without any SIM |url=https://techcrunch.com/2022/12/07/telegram-is-auctioning-phone-numbers-to-let-users-sign-up-to-the-service-without-any-sim/ |access-date=9 December 2022 |website=TechCrunch |language=en-US}} Changing the phone number in the app will automatically reassign the user's account to that number without the need to export data or notify their contacts.{{cite web |last=Munizaga |first=Jonathan |date=1 December 2014 |title=Telegram ya permite migrar conversaciones y contactos a una línea nueva |trans-title=Telegram already allows migrating conversations and contacts to a new line |url=http://www.wayerless.com/2014/12/telegram-se-actualiza-permitiendo-ahora-migrar-tus-conversaciones-y-contactos-a-una-linea-nueva/ |url-status=dead |archive-url=https://web.archive.org/web/20141219220850/http://www.wayerless.com/2014/12/telegram-se-actualiza-permitiendo-ahora-migrar-tus-conversaciones-y-contactos-a-una-linea-nueva/ |archive-date=19 December 2014 |access-date=2 December 2014 |publisher=Wayerless |language=es }}{{cite web |last=Mateo |first=David G |date=1 December 2014 |title=Telegram ahora permite traspasar mensajes al cambiar de número |url=http://www.tuexpertoapps.com/2014/12/02/telegram-ahora-permite-traspasar-mensajes-al-cambiar-de-numero/ |url-status=live |archive-url=https://web.archive.org/web/20190512143429/https://www.tuexpertoapps.com/2014/12/02/telegram-ahora-permite-traspasar-mensajes-al-cambiar-de-numero/ |archive-date=12 May 2019 |access-date=2 December 2014 |publisher=TuExperto |language=es}} Phone numbers are hidden by default with only a user's contacts being able to see them. Sign-ups can only be done via an Android or iOS device.{{cite web |last=Witman |first=Emma |date=22 January 2021 |title=How to make a Telegram account and start using the popular group chatting app |url=https://www.businessinsider.com/how-to-make-a-telegram-account |url-status=live |archive-url=https://web.archive.org/web/20210209074302/https://www.businessinsider.com/how-to-make-a-telegram-account |archive-date=9 February 2021 |access-date=28 May 2021 |website=Business Insider}}{{cite web |title=no login by sms code in desktop version |url=https://github.com/telegramdesktop/tdesktop/issues/16153 |url-status=live |archive-url=https://web.archive.org/web/20211028101131/https://github.com/telegramdesktop/tdesktop/issues/16153 |archive-date=28 October 2021 |access-date=10 July 2021 |website=GitHub}}

Upon signing up, messages sent and received by the user are tied to their number and a custom username,{{cite web |date=23 October 2014 |title=Secure Messaging App Telegram Adds Usernames And Snapchat-Like Hold-To-View For Media |url=https://techcrunch.com/2014/10/23/secure-messaging-app-telegram-adds-usernames-and-snapchat-like-hold-to-view-for-media/ |url-status=live |archive-url=https://web.archive.org/web/20190512143411/https://techcrunch.com/2014/10/23/secure-messaging-app-telegram-adds-usernames-and-snapchat-like-hold-to-view-for-media/ |archive-date=12 May 2019 |access-date=23 October 2014 |publisher=Techcrunch}} not the device. Any Telegram content is synced between the user's logged-in devices automatically through cloud storage, except for device-specific secret chats. By default, any account that is inactive for 6 months is automatically deleted, though the period can be shortened or extended up to 18 months through the Settings menu. Telegram allows groups, bots and channels with a verified social media or Wikipedia page to be verified, but not individual user accounts.{{Cite web |title=Page Verification Guidelines |url=https://telegram.org/verify |url-status=live |archive-url=https://web.archive.org/web/20210114070820/https://telegram.org/verify |archive-date=14 January 2021 |access-date=12 January 2021 |website=Telegram}}{{Cite web |date=3 April 2020 |title=Coronavirus News and Verified Channels |url=https://telegram.org/blog/coronavirus |url-status=live |archive-url=https://web.archive.org/web/20210122205226/https://telegram.org/blog/coronavirus |archive-date=22 January 2021 |access-date=12 January 2021 |website=Telegram}}

Messages can contain formatted text, media, files up to 2 GB (4 GB with Premium), locations and audio or video messages recorded in-app. Telegram messages in private chats can be edited up to 48 hours after they were sent with an "edited" icon appearing to reflect changes, as well as deleted for both sides without a trace. Users have the option to delete messages and whole chats for both themself and other participants. Chats can be exported to preserve them via Telegram's Desktop client, although the saved data cannot be imported back into the user's account.

Users can however import chat history, including both messages and media, from WhatsApp, Line, and KakaoTalk due to data portability, either making a new chat to hold the messages or adding them to an existing one.{{Cite web |date=31 January 2021 |title=آخرین میخ تلگرام بر تابوت واتساپ |url=https://www.eghtesadonline.com/بخش-فناوری-64/502325-آخرین-میخ-تلگرام-بر-تابوت-واتس-اپ |url-status=live |archive-url=https://web.archive.org/web/20210205175049/https://www.eghtesadonline.com/%D8%A8%D8%AE%D8%B4-%D9%81%D9%86%D8%A7%D9%88%D8%B1%DB%8C-64/502325-%D8%A2%D8%AE%D8%B1%DB%8C%D9%86-%D9%85%DB%8C%D8%AE-%D8%AA%D9%84%DA%AF%D8%B1%D8%A7%D9%85-%D8%A8%D8%B1-%D8%AA%D8%A7%D8%A8%D9%88%D8%AA-%D9%88%D8%A7%D8%AA%D8%B3-%D8%A7%D9%BE |archive-date=5 February 2021 |access-date=1 February 2021 |website=اقتصاد آنلاین |language=fa}}{{Cite web |title=Telegram's latest update lets you import chat history from other apps |url=https://www.gsmarena.com/telegrams_latest_update_lets_you_import_chat_history_from_other_apps-news-47472.php |url-status=live |archive-url=https://web.archive.org/web/20210131214359/https://www.gsmarena.com/telegrams_latest_update_lets_you_import_chat_history_from_other_apps-news-47472.php |archive-date=31 January 2021 |access-date=1 February 2021 |website=GSMArena.com |language=en-US}}

As users can be logged into many devices at once, starting to type a message on one of them will create a "cloud draft" that syncs with others, so typing can be started on a phone and finished on a laptop, for example.{{Cite web |date=14 June 2016 |title=Telegram rolls out message drafts, picture in picture for iOS, video player for Android |url=https://venturebeat.com/2016/06/14/telegram-rolls-out-message-drafts-picture-in-picture-for-ios-video-player-for-android/ |url-status=live |archive-url=https://web.archive.org/web/20210525092951/https://venturebeat.com/2016/06/14/telegram-rolls-out-message-drafts-picture-in-picture-for-ios-video-player-for-android/ |archive-date=25 May 2021 |access-date=25 May 2021 |publisher=VentureBeat}}

Any message in any chat can be translated by opening the context menu. Premium users have the option to translate the whole chat with one click. Users can hide the translate button for messages written in specific languages.

Reactions can be used to respond to a message with emoji, with Premium users having access to more reaction choices and the ability to leave more reactions per message. Reactions are always on in private chats and can be enabled by admins in groups and channels with the ability to allow or exclude specific reactions. Reaction emoji play an animation with special effects when sent.{{Cite web |date=20 September 2022 |title=Telegram's new update brings more emoji fun and lots of quality of life improvements |url=https://www.xda-developers.com/telegram-update-for-september-2022/ |access-date=20 September 2022 |website=XDA |language=en-US}}{{cite web |last1=Schoon |first1=Ben |date=30 December 2021 |title=Telegram adds message reactions, bigger emoji animations, and more in latest update |url=https://9to5google.com/2021/12/30/telegram-adds-message-reactions-bigger-emoji-animations-and-more-in-latest-update/ |access-date=16 May 2022 |website=9to5Google}}

Users can also send stickers, which can be static, animated or video.{{cite web |last1=Itani |first1=Mahmoud |date=1 February 2022 |title=Telegram introduces video stickers, improved reactions, and more |url=https://www.xda-developers.com/telegram-video-stickers-improved-reactions/ |access-date=16 May 2022 |website=XDA}} Sticker packs are made by Telegram designers as well as regular users and can be shared via links. They use the WebP{{Cite web |date=25 June 2021 |title=Animated Backgrounds |url=https://telegram.org/blog/animated-backgrounds |url-status=live |archive-url=https://web.archive.org/web/20210626105339/https://telegram.org/blog/animated-backgrounds |archive-date=26 June 2021 |access-date=27 June 2021 |website=Telegram}} or WebM format and do not require special software to create or upload. Some stickers feature full-screen effects that play out when first sent or when tapped.

Users can schedule messages to send at a particular time or when their conversation partner comes online,{{Cite web |date=1 January 2020 |title=Telegram 5.13 update brings Theme Editor 2.0, "Send when online", verifiable builds, and more |url=https://www.xda-developers.com/telegram-5-13-update-brings-theme-editor-2-0-more/ |url-status=live |archive-url=https://web.archive.org/web/20201209123902/https://www.xda-developers.com/telegram-5-13-update-brings-theme-editor-2-0-more/ |archive-date=9 December 2020 |access-date=7 August 2020}} as well as choose to send a message "without sound" without a notification. Messages from private chats can be forwarded, with an option to hide the original sender's identity or to hide captions from media messages. Forwarded messages also maintain reply formatting, able to show which messages in a thread are replying to others. Any user can also send a message to a special "Saved Messages" chat as a form of bookmarking them. The contents of the chat are only visible to the user.

Chats can be sorted into folders to organize them with preset options like "Unread" and "Muted? or custom separations such as "Work" and "Family". Premium users have the ability to set any chat folder as the default screen in the app while regular users will always see the full chat list when first opening the app.File:A "secret chat" confirmation notice in Telegram.jpg]]

Users have the option to start a one-on-one, end-to-end-encrypted "Secret Chat", which remains accessible only on the device where it was started and self-destructs upon logging out.{{cite web |title=FAQ: How secure is Telegram? |url=https://telegram.org/faq#q-how-secure-is-telegram |url-status=live |archive-url=https://web.archive.org/web/20140209082001/https://telegram.org/faq#q-how-secure-is-telegram |archive-date=9 February 2014 |access-date=10 February 2014 |work=Telegram official website}}{{cite web |title=Description of MTProto Mobile Protocol |url=https://core.telegram.org/mtproto |url-status=live |archive-url=https://web.archive.org/web/20141006104149/https://core.telegram.org/mtproto |archive-date=6 October 2014 |access-date=7 March 2014 |publisher=Telegram}} Secret Chats restrict screenshotting from Android devices and warn when one is taken from an iOS device, while also hiding the chat contents from the final image.{{cite web |last1=Hamburger |first1=Ellis |date=25 February 2014 |title=Why Telegram has become the hottest messaging app in the world |url=https://www.theverge.com/2014/2/25/5445864/telegram-messenger-hottest-app-in-the-world |url-status=live |archive-url=https://web.archive.org/web/20160313050911/http://www.theverge.com/2014/2/25/5445864/telegram-messenger-hottest-app-in-the-world |archive-date=13 March 2016 |access-date=17 March 2016 |website=The Verge |publisher=Vox Media}} Secret Chats support perfect forward secrecy and switch encryption keys after a key has been used 100 times or a week has passed.{{harvnb|Rottermanner|Kieseberg|Huber|Schmiedecker|2015|p=2}}{{cite web |date=14 December 2014 |title=Perfect Forward Secrecy |url=https://core.telegram.org/api/end-to-end/pfs |url-status=live |archive-url=https://web.archive.org/web/20191107005120/https://core.telegram.org/api/end-to-end/pfs |archive-date=7 November 2019 |access-date=14 December 2014 |publisher=Telegram}}{{harvnb|Rottermanner|Kieseberg|Huber|Schmiedecker|2015|p=6}} Secret Chats are only available on Android, iOS and macOS clients.{{cite web |date=2 July 2015 |title=Github issue 871: missing secret chats |url=https://github.com/telegramdesktop/tdesktop/issues/871 |url-status=live |archive-url=https://web.archive.org/web/20190502055013/https://github.com/telegramdesktop/tdesktop/issues/871 |archive-date=2 May 2019 |access-date=25 July 2017 |website=GitHub}}

Both in Secret and regular chats, messages can self-destruct after they are read, disappearing for all parties after a period set by the user, ranging from 1 day to 1 year.{{Cite web |date=27 February 2021 |title=How Telegram's new update is making messages private |url=https://www.livemint.com/technology/tech-news/how-telegram-s-new-update-is-making-messages-private-11614388851319.html |url-status=live |archive-url=https://web.archive.org/web/20210228184333/https://www.livemint.com/technology/tech-news/how-telegram-s-new-update-is-making-messages-private-11614388851319.html |archive-date=28 February 2021 |access-date=1 March 2021 |website=mint |language=en}}{{cite web |date=3 January 2017 |title=Unsend Messages, Network Usage, and More |url=https://telegram.org/blog/unsend-and-usage |url-status=live |archive-url=https://web.archive.org/web/20191210213549/https://telegram.org/blog/unsend-and-usage |archive-date=10 December 2019 |access-date=4 April 2017 |publisher=Telegram}}

Telegram users can create and join groups and channels. Groups are large multi-user chats that support up to 200,000 members and can be public or private. Users can freely join public chats and find them using the in-app search function, while private chats require an invitation. They support flexible admin rights and can use bots for moderation to prevent spam and unwanted activity. Groups can be split into topics, effectively creating subgroups dedicated to various subjects with separate settings for each.{{Cite web |author1=Nickolas Diaz |date=7 November 2022 |title=Telegram drops an update, adds topics in groups, Voice-to-Text, and new emoji packs |url=https://www.androidcentral.com/apps-software/telegram-update-voice-to-text-video-group-topics-collectible-usernames |access-date=17 December 2023 |website=Android Central |language=en}}

Admins can choose to hide the list of members in a group, as well as post anonymously themselves.{{Cite web |last=Potts |first=Caleb |date=30 September 2020 |title=Telegram adds search filters, anonymous admins, channel replies, and more |url=https://www.androidpolice.com/2020/09/30/telegram-adds-search-filters-anonymous-admins-channel-replies-and-more/ |access-date=17 December 2023 |website=Android Police |language=en}} Similarly, groups and channels can have content protection enabled, which prevents screenshots, forwarding and downloading of media.{{Cite web |date=8 December 2021 |title=Telegram monthly update brings Content Protection and Delete by Date feature |url=https://indianexpress.com/article/technology/social/telegram-monthly-update-brings-content-protection-and-delete-by-date-feature-7662617/ |access-date=17 December 2023 |website=The Indian Express |language=en}}{{cite web |last=Gatlan |first=Sergiu |date=8 December 2021 |title=Telegram adds content protection support for groups and channels |url=https://www.bleepingcomputer.com/news/software/telegram-adds-content-protection-support-for-groups-and-channels/ |url-status=live |archive-url=https://web.archive.org/web/20211223225101/https://www.bleepingcomputer.com/news/software/telegram-adds-content-protection-support-for-groups-and-channels/ |archive-date=23 December 2021 |access-date=27 December 2021 |website=Bleeping Computer |language=en-US}} Ownership of channels and groups can be transferred to one of the admins if the owner wishes to give up their rights.

Groups support threaded replies, where bringing up the context menu on a message allows one to open a screen with a thread of replies made to that message and the subsequent ones in the thread. Specific users can be tagged in the group by adding @username to a message, where "username" is that particular user's username.

Groups and channels also support polls, which can be open or anonymous and can support multiple choices. When forwarded, polls retain the answer data and any votes cast in other chats will count toward the overall total.{{Cite web |date=24 January 2020 |title=Telegram introduces a new feature that WhatsApp doesn't have: Poll 2.0 |url=https://tech.hindustantimes.com/tech/news/telegram-introduces-a-new-feature-that-whatsapp-doesn-t-have-poll-2-0-story-pOkzTJb1xvPl87Ic5ya9XI.html |access-date=17 December 2023 |website=HT Tech |language=en}}{{cite web |date=23 January 2020 |title=Telegram 5.14 adds multiple-answer and quiz polls (APK Download) |url=https://www.androidpolice.com/2020/01/23/telegram-5-14-adds-multiple-answer-and-quiz-polls-apk-download/ |url-status=live |archive-url=https://web.archive.org/web/20210603124745/https://www.androidpolice.com/2020/01/23/telegram-5-14-adds-multiple-answer-and-quiz-polls-apk-download/ |archive-date=3 June 2021 |access-date=3 June 2021 |website=Android Police}}

Channels are one-way feeds where the channel owner or admins can post content while followers can only read, react and comment, if comments have been enabled.{{cite web |date=30 September 2020 |title=Telegram adds search filters, anonymous admins, channel replies, and more |url=https://www.androidpolice.com/2020/09/30/telegram-adds-search-filters-anonymous-admins-channel-replies-and-more/ |url-status=live |archive-url=https://web.archive.org/web/20210125050457/https://www.androidpolice.com/2020/09/30/telegram-adds-search-filters-anonymous-admins-channel-replies-and-more/ |archive-date=25 January 2021 |access-date=25 May 2021 |website=Android Police}}{{cite web |date=1 June 2019 |title=Telegram 5.7 further enhances privacy, improves group and channel features, and more |url=https://www.androidpolice.com/2019/06/01/telegram-5-7-further-enhances-privacy-improves-group-and-channel-features-and-more/ |url-status=live |archive-url=https://web.archive.org/web/20210525092954/https://www.androidpolice.com/2019/06/01/telegram-5-7-further-enhances-privacy-improves-group-and-channel-features-and-more/ |archive-date=25 May 2021 |access-date=25 May 2021 |website=Android Police}} Channels can be created for broadcasting messages to an unlimited number of subscribers.{{cite news |last1=Lobao |first1=Martim |date=22 September 2015 |title=Telegram v3.2 Brings Channels For Broadcasting Your Messages To The World |work=Android Police |url=http://www.androidpolice.com/2015/09/22/telegram-v3-2-brings-channels-broadcasting-messages-world/ |url-status=live |access-date=5 February 2016 |archive-url=https://web.archive.org/web/20190512175942/https://www.androidpolice.com/2015/09/22/telegram-v3-2-brings-channels-broadcasting-messages-world/ |archive-date=12 May 2019}} The list of those who subscribe to a channel can only be seen by its admins. Posting in the channel is anonymous, though admins can choose to add signatures to their posts. Channels offer detailed statistics on view counts, user growth and interactions, also visible only to admins.{{Cite web |date=16 December 2023 |title=Telegram 6.0 adds chat folders, channel statistics, and more |url=https://www.neowin.net/news/telegram-60-adds-chat-folders-channel-statistics-and-more/ |access-date=17 December 2023 |website=Neowin |language=en}}

Channel owners are able to use Telegram to create giveaways, randomly awarding channel members with prizes such as Telegram Premium subscriptions to their followers, based on certain criteria.{{Cite web |last=Vasile |first=Cosmin |date=7 November 2023 |title=Telegram update brings the ability to host giveaways |url=https://www.phonearena.com/news/telegram-update-channel-giveaways_id152336 |access-date=7 November 2023 |website=PhoneArena |language=en-US}} Users with a Telegram Premium subscription have a number of "boosts" that they can give to channels, which allow the channel to "level up" and unlock features, such as the ability to customize messages or post stories as the channel.{{Cite web |last=Kellen |date=22 September 2023 |title=Telegram Adds Stories for Channels Where You Have All the Power |url=https://www.droid-life.com/2023/09/22/telegram-channel-stories-boost/ |access-date=17 December 2023 |website=www.droid-life.com |language=en-US}}

In December 2019, Bloomberg News moved their messenger-based newsletter service from WhatsApp to Telegram after the former banned bulk and automated messaging.{{cite news|url=https://www.bloomberg.com/news/articles/2019-12-04/how-to-follow-bloomberg-on-telegram|title=How to Follow Bloomberg on Telegram|last=Hess|first=Megan|date=3 December 2019|newspaper=Bloomberg.com|access-date=10 January 2020|archive-date=8 December 2020|archive-url=https://web.archive.org/web/20201208134608/https://www.bloomberg.com/news/articles/2019-12-04/how-to-follow-bloomberg-on-telegram|url-status=live}}{{cite web|url=https://digiday.com/media/bloomberg-news-using-telegram/|title=How Bloomberg News is using Telegram|last=Ting|first=Deanna|date=10 January 2020|website=Digiday|language=en-US|access-date=10 January 2020|archive-date=9 December 2020|archive-url=https://web.archive.org/web/20201209095859/https://digiday.com/media/bloomberg-news-using-telegram/|url-status=live}} Other news services with official channels on the platform include the Financial Times,{{cite web |title=Join the FT Telegram channel to receive Ukraine coverage alerts |url=https://www.ft.com/telegram |website=Financial Times |date=24 March 2020 |access-date=1 May 2022}} Business Insider{{cite web |last1=Mahal |first1=Pavan |title=Sign up for Telegram updates from Business Insider |url=https://www.businessinsider.com/sign-up-for-telegram-updates-business-insider-2021-1 |website=Business Insider |access-date=1 May 2022}} and The New York Times.{{cite news |title=The New York Times launches a Telegram channel to deliver news about the war. |url=https://www.nytimes.com/2022/03/14/world/europe/telegram-nyt.html |website=The New York Times |date=14 March 2022 |access-date=1 May 2022}}

Channels have also been used by governments and heads of state. Notable examples include Volodymyr Zelenskyy{{cite magazine |last1=Bergengruen |first1=Vera |date=21 March 2022 |title=How Telegram Became the Digital Battlefield in the Russia-Ukraine War |url=https://time.com/6158437/telegram-russia-ukraine-information-war/ |access-date=1 May 2022 |magazine=TIME }} and Emmanuel Macron.{{cite web |title=Telegram: Contact @emmanuelmacron |url=https://t.me/emmanuelmacron |website=Telegram |access-date=1 May 2022}} Channels have been used by journalists in oppressive regimes to establish independent news networks.{{cite magazine |last1=Ptak |first1=Guillaume |title=The Telegram-Powered News Outlet Waging Guerrilla War on Russia |url=https://www.wired.com/story/february-morning-russia-ukraine-war/ |magazine=Wired |date=29 August 2022 |access-date=30 August 2022}}

Telegram also provides an open API for the creation of custom bots which can perform various tasks, integrate other services into Telegram chats, or work as mini apps or games.{{cite web | url=https://ton.org/mini-apps | title=Telegram Mini Apps }}{{Cite web |last=Russell |first=Jon |date=18 May 2017 |title=Telegram now lets users buy things from chatbots in its messaging app |url=https://techcrunch.com/2017/05/18/telegram-launches-chatbot-payments/ |access-date=17 October 2023 |website=TechCrunch |language=en-US}} Most of them work on the 8XR game engine.{{Cite web |title=Telegram Games |url=https://t.me/gam8s |access-date=20 May 2024 |website=Telegram}}{{Cite web |last=Platform |first=The Open |date=17 November 2023 |title=From Bots to Mini Apps: Unveiling Telegram's Web3 Ecosystem |url=https://topco.medium.com/from-bots-to-mini-apps-unveiling-telegrams-web3-ecosystem-edea254f9b5f |access-date=20 May 2024 |website=Medium |language=en}} In July 2024, Telegram Mini Apps reached 500 million monthly active users.{{cite web | url=https://www.blockchaingamer.biz/news/35861/animoca-reports-34-million-active-ton-wallets/ | title=Animoca reports 34 million active wallets on TON | date=3 December 2024 }}

Since 2017, Telegram users have been able to initiate one-on-one calls in private chats. Calls are end-to-end encrypted and prioritize peer-to-peer connections. Video calls were introduced in August 2020.{{Cite web |last=Lyons |first=Kim |date=15 August 2020 |title=Telegram launches one-on-one video calls on iOS and Android |url=https://www.theverge.com/2020/8/15/21370420/telegram-video-calls-os-android |access-date=28 January 2024 |website=The Verge |language=en}}{{Cite web |last=O'Flaherty |first=Kate |title=Telegram Just Launched A Major New Feature To Beat Zoom |url=https://www.forbes.com/sites/kateoflahertyuk/2020/08/16/telegram-just-launched-a-major-new-feature-to-beat-zoom/ |url-status=live |archive-url=https://web.archive.org/web/20201209111454/https://www.forbes.com/sites/kateoflahertyuk/2020/08/16/telegram-just-launched-a-major-new-feature-to-beat-zoom/ |archive-date=9 December 2020 |access-date=3 September 2020 |website=Forbes |language=en}} According to Telegram, there is a neural network working to learn various technical parameters about a call to provide better quality of service for future uses.{{cite web |url=https://techcrunch.com/2017/03/30/telegram-call/ |publisher=TechCrunch |title=Telegram introduces voice calls, touting end-to-end encryption |date=30 March 2017 |access-date=25 May 2021 |archive-date=25 May 2021 |archive-url=https://web.archive.org/web/20210525092951/https://techcrunch.com/2017/03/30/telegram-call/ |url-status=live }}

Telegram added group voice chats in December 2020{{Cite web|title=Telegram gets Discord-like group voice chats|url=https://www.theverge.com/2020/12/23/22196894/telegram-voice-chats-group-discord-feature|access-date=23 December 2020|website=www.theverge.com|date=23 December 2020|language=en|archive-date=23 December 2020|archive-url=https://web.archive.org/web/20201223172226/https://www.theverge.com/2020/12/23/22196894/telegram-voice-chats-group-discord-feature|url-status=live}} and group video chats in June 2021.{{Cite web |last=Serrano |first=Jody |date=27 June 2021 |title=A Year Later, Telegram Finally Launches the Group Video Calls It Promised |url=https://gizmodo.com.au/2021/06/a-year-later-telegram-finally-launches-the-group-video-calls-it-promised/ |access-date=28 January 2024 |website=Gizmodo Australia |language=en-AU}} Group voice and video chats support picture-in-picture video, as well as sharing one's screen, creating a recording of the call, noise suppression and selective muting.{{cite web |last=Kew-Denniss |first=Zachary |date=25 June 2021 |title=Group video calls and animated backgrounds are finally here in Telegram 7.8 |url=https://www.androidpolice.com/2021/06/25/telegram-beta-7-8-adds-video-and-screen-sharing-in-groups/ |url-status=live |archive-url=https://web.archive.org/web/20210625191110/https://www.androidpolice.com/2021/06/25/telegram-beta-7-8-adds-video-and-screen-sharing-in-groups/ |archive-date=25 June 2021 |access-date=26 June 2021 |work=Android Police}}{{cite web |last=Lyons |first=Kim |date=26 June 2021 |title=Telegram adds group video calling at last |url=https://www.theverge.com/2021/6/26/22551652/telegram-adds-group-video-calling-chat |url-status=live |archive-url=https://web.archive.org/web/20210626140818/https://www.theverge.com/2021/6/26/22551652/telegram-adds-group-video-calling-chat |archive-date=26 June 2021 |access-date=26 June 2021 |work=The Verge}}{{Cite web |date=25 June 2021 |title=Group Video Calls |url=https://telegram.org/blog/group-video-calls |url-status=live |archive-url=https://web.archive.org/web/20210625224638/https://telegram.org/blog/group-video-calls |archive-date=25 June 2021 |access-date=27 June 2021 |website=Telegram}} In channels, users can start a livestream, that is able to integrate with third-party apps such as OBS Studio and XSplit.{{Cite web |url=https://telegram.org/blog/live-streams-forwarding-next-channel |title=Live Streams, Flexible Forwarding, Jump to Next Channel, Trending Stickers and More |date=31 August 2021 |access-date=8 December 2021 |archive-date=8 December 2021 |archive-url=https://web.archive.org/web/20211208183034/https://telegram.org/blog/live-streams-forwarding-next-channel |url-status=live }}{{cite web |last1=Bonggolto |first1=Jay |title=Telegram picks up a new download manager and redesigns its attachment menu |url=https://www.androidcentral.com/telegram-update-download-manager-attachment-menu-live-streaming-with-third-party-apps |website=Android Central |date=11 March 2022 |access-date=21 May 2022}}

Once launched, a group voice chat will remain active and open to all group members until an admin specifically closes it.{{Cite web |last=Warren |first=Tom |date=23 December 2020 |title=Telegram gets Discord-like group voice chats |url=https://www.theverge.com/2020/12/23/22196894/telegram-voice-chats-group-discord-feature |access-date=28 January 2024 |website=The Verge |language=en}}

In April 2025, Telegram launched secure group calls with end-to-end encryption by using blockchain-like encryption technology. Group calls can handle up to 200 participants, and provide voice/video calls and screen sharing.{{Cite web|title=Telegram Deploys Blockchain-Inspired Encryption for Group Calls That Supports 'Tens of Thousands' of Participants|url=https://www.ccn.com/news/technology/telegram-blockchain-inspired-encryption/|website=www.ccn.com |date=5 May 2025 |access-date=5 May 2025 |language=en}}

By default, logging into Telegram requires either an SMS message sent to the registered number or a code message sent to one of the active sessions on another device. Users have the option to set a two-step verification password and add a recovery email.{{Cite magazine |author=Yasmin Ahmed |date=5 June 2020 |title=Telegram adds two-step verification for better security, launches in-app video editor to platform |url=https://www.indiatoday.in/technology/news/story/telegram-adds-two-step-verification-for-better-security-launches-in-app-video-editor-to-platform-1685933-2020-06-05 |url-status=live |archive-url=https://web.archive.org/web/20201219051314/https://www.indiatoday.in/technology/news/story/telegram-adds-two-step-verification-for-better-security-launches-in-app-video-editor-to-platform-1685933-2020-06-05 |archive-date=19 December 2020 |access-date=11 December 2020 |magazine=India Today |language=en}} In late 2022, options to Sign in with Apple and Sign In with Google or with an email address were added.{{Cite web |title=Beta Info English |url=https://t.me/s/betainfoen/1032 |access-date=18 January 2023 |website=Telegram}} Whenever a new device successfully logs in to a user's account, a special service notification is sent and a login alert is displayed in the chat list of their other devices.{{Cite web |title=Telegram update brings stories in Channels, better login alerts and more {{!}} Technology |url=https://www.devdiscourse.com/article/technology/2604607-telegram-update-brings-stories-in-channels-better-login-alerts-and-more |access-date=14 January 2024 |website=Devdiscourse |language=en}}

In the Privacy and Security submenu of Settings, users have the option to hide their "Last Seen" status,{{Cite web |title=How to Hide Last Seen on Telegram |url=https://www.alphr.com/how-to-hide-last-seen-on-telegram/ |access-date=14 January 2024 |website=Alphr |date=6 June 2023 |language=en-US}} which reflects the last time the user opened a Telegram app. Hiding the status obfuscates the exact time of the user being online and hides the statuses of other people respectively. Similarly, users can hide their phone number and profile photo from people based on categories such as Non-Contacts or by adding exceptions. When a user chooses to hide their profile photo, they have an option of setting an alternative "Public Profile Picture" that will be shown instead.{{Cite web |last=Kellen |date=30 December 2022 |title=Telegram's 10 New Features are Its Best in a While |url=https://www.droid-life.com/2022/12/30/telegram-update-adds-spoiler-alerts-profile-pic-controls-and-lots-more/ |access-date=14 January 2024 |website=www.droid-life.com |language=en-US}}

In the same menu, users can restrict the circle of people who can call them or invite them to groups and channels, while Premium users also have the option to restrict who can send them voice messages.{{Cite web |last=Espósito |first=Filipe |date=13 August 2022 |title=Telegram update approved in App Store after Apple complained about animated emoji |url=https://9to5mac.com/2022/08/13/telegram-app-store-apple-complained-emoji/ |access-date=14 January 2024 |website=9to5Mac}}

The Devices submenu shows all of the active devices on a user's account and allows them to remotely log out from those devices.{{Cite web |last1=Gilbert |first1=Jon |last2=Mascellino |first2=Alessandro |date=22 March 2022 |title=Top 10 tips for using Telegram safely and securely |url=https://www.androidpolice.com/top-tips-using-telegram-safely-securely/ |access-date=14 January 2024 |website=Android Police |language=en}}

Telegram clients have the ability to turn off media autoplay and automatic downloads for both WiFi and mobile data, adjusting them for media type and size. Auto download settings can also be applied based on chat type such as group, channel or private.

Cache settings can be changed to automatically clear the cache once it reaches a certain size or a certain time passes. The interface shows users a visual representation of their storage usage and also lets them sort their cached media by size to clear specific items.{{Cite web |last=Potuck |first=Michael |date=30 December 2022 |title=Telegram for iOS gets new drawing and text tools, updates for hidden media, zero storage use, more |url=https://9to5mac.com/2022/12/30/telegram-ios-update-2/ |access-date=14 January 2024 |website=9to5Mac}}

In June 2015, Telegram launched a platform for third-party developers to create bots.{{cite web|url=https://telegram.org/blog/bot-revolution|publisher=Telegram|title=Telegram Bot Platform|date=24 June 2015|access-date=1 September 2015|archive-date=12 December 2019|archive-url=https://web.archive.org/web/20191212053626/https://telegram.org/blog/bot-revolution|url-status=live}} Bots are Telegram accounts operated by programs. They can respond to messages or mentions directly or can be invited into groups, and are able to perform tasks, integrate with other programs and host mini apps.{{Cite web |last=Liao |first=Rita |date=26 September 2023 |title=Telegram starts to look like a super app, echoing WeChat |url=https://techcrunch.com/2023/09/25/telegram-wechat-super-app-ton-foundation/ |access-date=14 January 2024 |website=TechCrunch |language=en-US}}{{Cite web |title=Telegram Mini Apps |url=https://core.telegram.org/bots/webapps |access-date=14 January 2024 |website=core.telegram.org}} Bots can accept online payments made with credit cards or Apple Pay.{{cite web|url=https://telegram.org/blog/payments|title=Payments for Bots|website=Telegram|date=18 May 2017|access-date=12 February 2018|archive-date=9 May 2019|archive-url=https://web.archive.org/web/20190509215757/https://telegram.org/blog/payments|url-status=live}} The Dutch website Tweakers reported that an invited bot can potentially read all group messages, when the bot controller changes the access settings silently at a later point in time. Telegram pointed out that it considered implementing a feature that would announce such a status change within the relevant group.{{cite news|url = http://tweakers.net/nieuws/104386/telegram-bots-kunnen-relatief-ongemerkt-meelezen-in-groepsgesprekken.html|title = Telegram-bots kunnen relatief ongemerkt meelezen in groepsgesprekken|date = 23 July 2015|access-date = 25 October 2015|website = Tweakers|last = Schellevis|first = Joost|language = nl|archive-date = 12 May 2019|archive-url = https://web.archive.org/web/20190512150205/https://tweakers.net/nieuws/104386/telegram-bots-kunnen-relatief-ongemerkt-meelezen-in-groepsgesprekken.html|url-status = live}}

There are also inline bots, which can be used from any chat screen. To activate an inline bot, a user must type the bot's username and a query in the message field. The bot then will offer its content. The user can choose from that content and send it within a chat.{{cite web|url=https://telegram.org/blog/inline-bots|publisher=Telegram|title=Introducing Inline Bots|date=4 January 2016|access-date=4 April 2017|archive-date=9 August 2019|archive-url=https://web.archive.org/web/20190809155850/https://telegram.org/blog/inline-bots|url-status=live}} Certain approved bots are also able to integrate into the attachment menu, making them accessible in any chat.{{Cite web |title=Launching Mini Apps from the Attachment Menu |url=https://core.telegram.org/bots/webapps#launching-mini-apps-from-the-attachment-menu |access-date=14 January 2024 |website=core.telegram.org}}

Bots can handle transactions provided by Paymentwall, Yandex.Money, Stripe, Ravepay, Razorpay, QiWi and Google Pay for different countries.{{Cite web|url=https://telegram.org/blog/payments|title=Payments for Bots|date=18 May 2017|website=Telegram|access-date=12 February 2018|archive-date=9 May 2019|archive-url=https://web.archive.org/web/20190509215757/https://telegram.org/blog/payments|url-status=live}} Bots power Telegram's gaming platform, which utilizes HTML5, so games are loaded on-demand as needed, like ordinary webpages. Games work on iPhone 4 and newer, and on Android 4.4 devices and newer.{{Cite web|url=https://telegram.org/blog/games|title=Gaming Platform 1.0|date=3 October 2016|website=Telegram|access-date=16 August 2020|archive-date=9 August 2020|archive-url=https://web.archive.org/web/20200809190314/https://telegram.org/blog/games|url-status=live}}

People can use Internet Of Things (IoT) services with two-way interaction via IFTTT implemented within Telegram.{{Cite web|url=https://telegram.org/blog/pin-and-ifttt|title=Pinned Chats and IFTTT Integrations|date=7 December 2016|website=Telegram|access-date=16 August 2020|archive-date=9 December 2020|archive-url=https://web.archive.org/web/20201209081235/https://telegram.org/blog/pin-and-ifttt|url-status=live}}

File:Telegram android app test receipt order Screenshot 20210627.png

In April 2021, the Payments 2.0 upgrade enabled bot payments within any chat, using third-party services such as Sberbank, Tranzoo, Payme, CLICK, LiqPay and ECOMMPAY to process the credit card information.{{Cite web|date=27 April 2021|title=Telegram now lets retailers accept credit cards in any chat|url=https://www.windowscentral.com/telegram-adds-new-payment-features-latest-update|access-date=27 April 2021|website=Windows Central|language=en|archive-date=27 April 2021|archive-url=https://web.archive.org/web/20210427155309/https://www.windowscentral.com/telegram-adds-new-payment-features-latest-update|url-status=live}}

In February 2018, Telegram launched their social login feature to its users, named Telegram Login. It features a website widget that could be embedded into websites, allowing users to sign into a third party website with their Telegram account. The gateway sends the user's Telegram name, username, and profile picture to the website owner, while the user's phone number remains hidden. The gateway is integrated with a bot, which is linked with the developer's specific website domain.{{Cite news|title=Telegram 4.8 arrives with Telegram Login and streaming|language=en|work=Neowin|url=https://www.neowin.net/news/telegram-48-arrives-with-telegram-login-and-streaming|access-date=12 February 2018|archive-date=18 May 2019|archive-url=https://web.archive.org/web/20190518221145/https://www.neowin.net/news/telegram-48-arrives-with-telegram-login-and-streaming|url-status=live}}

In June 2021, an update introduced a new bot menu where users can browse and send commands while in a chat with a bot.

In April 2022, bots gained support for customized interfaces and inline page loading. Interfaces can be adjusted to match the app's theme even if it changes while interacting with the bot.{{Cite web |date=16 April 2022 |title=Notification Sounds, Bot Revolution and More |url=https://telegram.org/blog/notifications-bots |access-date=14 January 2024 |website=Telegram}}

In October 2024, Telegram added increased messaging limits for bots, allowing bots to send up to 1000 messages per second to their users. Messages beyond the free limit of 30 per second are paid for using Telegram Stars.{{Cite web |title=Telegram update brings Faster video loading, Playback speed options, Last edit timestamps and more |url=https://www.fonearena.com/blog/439282/telegram-faster-video-loading-playback-speed-options-last-edit-timestamps.html |access-date=7 November 2024 |website=www.fonearena.com}}

Telegram introduced affiliate programs in December 2024, which allow developers to create an affiliate program for their bot or mini app. Any Telegram user can join the affiliate program, and are rewarded for referring others to the bot or mini app by receiving a commission from purchases made by the people they referred.{{Cite web |last=Vasile |first=Cosmin |date=6 December 2024 |title=Telegram launches referral program for mini app creators, improved sticker search |url=https://www.phonearena.com/news/telegram-affiliate-programs-sticker-search-collages_id165591 |access-date=18 December 2024 |website=PhoneArena |language=en-US}}

Telegram has more than 40,000 stickers. Stickers are cloud-based, high-resolution images intended to provide more expressive emoji. When typing in an emoji, the user is offered to send the respective sticker instead. Stickers come in collections called "packs", and multiple stickers can be offered for one emoji. Telegram comes with one default sticker pack,{{cite web|url=https://telegram.org/blog/stickers-meet-art-and-history|publisher=Telegram|title=Telegram Stickers|date=2 January 2015|access-date=5 January 2016|archive-date=6 August 2019|archive-url=https://web.archive.org/web/20190806091723/https://telegram.org/blog/stickers-meet-art-and-history|url-status=live}} and users can install additional sticker packs provided by third-party contributors.

Sticker sets installed from one client become automatically available to all other clients. Sticker images use WebP file format, which is better optimized to be transmitted over the internet. The Telegram clients also support animated emoji. In January 2022, video stickers were added, which use the WebM file format and do not feature any software requirements to create.{{cite web |last1=Itani |first1=Mahmoud |title=Telegram introduces video stickers, improved reactions, and more |url=https://www.xda-developers.com/telegram-video-stickers-improved-reactions/ |website=XDA |date=1 February 2022 |access-date=16 May 2022}}

In August 2019, Telegram introduced animated emoji,{{Cite web |title=The Evolution of Telegram |url=https://telegram.org/evolution#august-2019 |access-date=3 June 2024 |website=Telegram}} larger versions of familiar emoji with unique animations. In September 2021, Telegram added interactive emoji, a type of animated emoji which also play a fullscreen effect in the chat.{{Cite web |title=The Evolution of Telegram |url=https://telegram.org/evolution#september-2021 |access-date=3 June 2024 |website=Telegram}} These kinds of effects were later used for Premium Stickers in June 2022{{Cite web |title=The Evolution of Telegram |url=https://telegram.org/evolution#june-2022 |access-date=3 June 2024 |website=Telegram}} and for message effects in May 2024.{{Cite web |date=31 May 2024 |title=Message Effects, Hashtag Search, and More |url=https://telegram.org/blog/message-effects-and-more |access-date=3 June 2024 |website=Telegram}}

In August 2022, Telegram launched an emoji platform where users could upload their own custom emoji, either in animated or static versions.{{Cite web |title=The Evolution of Telegram |url=https://telegram.org/evolution#august-2022 |access-date=3 June 2024 |website=Telegram}} While any user can upload custom emoji to the platform, the use of custom emoji in chats is only available to users with Telegram Premium.{{Cite web |last=OLUKOTUN |first=OLUWASEGUN |title=Telegram introduces its Emoji Platform, rolls out Custom Animated Emoji Packs, Gifting Telegram Premium, and More |url=https://innovation-village.com/telegram-introduces-its-emoji-platform-rolls-out-custom-animated-emoji-packs-gifting-telegram-premium-and-more/ |access-date=3 June 2024 |website=innovation-village.com|date=16 August 2022 }}

Reactions were first added to Telegram in 2021{{Cite web |title=The Evolution of Telegram |url=https://telegram.org/evolution#december-2021-second-update |access-date=3 June 2024 |website=Telegram}} and expanded to include more emoji options for Premium users. In September 2022, Telegram gave free users access to dozens of reactions, even some that were only previously available to Premium subscribers. In order to accommodate the new reactions, the reaction panel was expanded and redesigned.

People Nearby can help users meet new friends by turning on phone GPS location and opting-in contacts and through Groups Nearby people can create a local group by adding location data to groups.{{Cite web |url=https://techcrunch.com/2019/06/25/telegram-adds-location-flavored-extras-and-full-group-ownership-transfers/ |title=Telegram adds location-flavored extras and full group ownership transfers |date=25 June 2019 |website=TechCrunch |access-date=3 June 2021 |archive-date=3 June 2021 |archive-url=https://web.archive.org/web/20210603124745/https://techcrunch.com/2019/06/25/telegram-adds-location-flavored-extras-and-full-group-ownership-transfers/ |url-status=live }}{{Cite web|url = https://telegram.org/blog/protected-content-delete-by-date-and-more|title = Protected Content, Delete by Date, Device Management and More|date = 7 December 2021|access-date = 8 December 2021|archive-date = 8 December 2021|archive-url = https://web.archive.org/web/20211208180925/https://telegram.org/blog/protected-content-delete-by-date-and-more|url-status = live}}

In 2024 the "people nearby" and "groups near me" features were removed, which Durov said had “issues with bots and scammers”.{{Cite news |last1=Milmo |first1=Dan |last2=Sauer |first2=Pjotr |date=6 September 2024 |title=Telegram to drop 'people nearby' feature and improve moderation |url=https://www.theguardian.com/technology/article/2024/sep/06/telegram-to-drop-people-nearby-feature-and-improve-moderation |access-date=7 September 2024 |work=The Guardian |language=en-GB |issn=0261-3077}}

Similar to other social platforms, Telegram users can post stories, a type of short-form content. Telegram stories have several distinctive features, like a dual-camera mode, extra privacy settings, the ability to edit stories after posting them, as well as to rewind and fast-forward them while watching.{{Cite web |date=15 August 2023 |title=Telegram stories are finally available to everyone |url=https://www.androidpolice.com/telegram-10-update-stories-available/ |access-date=21 August 2023 |website=Android Police |language=en}}{{Cite web |last=Malik |first=Aisha |date=14 August 2023 |title=Telegram rolls out its Stories feature to all users |url=https://techcrunch.com/2023/08/14/telegram-rolls-out-its-stories-feature-to-all-users/ |access-date=21 August 2023 |website=TechCrunch |language=en-US}}{{Cite web |title=Telegram: Telegram rolls out new features with Halloween update: Replies 2.0, adjustable link previews and more |url=https://www.gadgetsnow.com/apps/telegram-rolls-out-new-features-with-halloween-update-replies-2-0-adjustable-link-previews-and-more/articleshow/104832900.cms |access-date=31 October 2023 |website=Gadgets Now |language=en}}

Telegram Premium was launched on 19 June 2022 with regional pricing. The optional paid subscription gives users increased limits in the app, such as larger file uploads, faster download speeds, unlimited voice message transcription,{{Cite web |last=Weatherbed |first=Jess |date=1 December 2023 |title=Telegram opens up voice transcription to all users in latest update |url=https://www.theverge.com/2023/12/1/23983851/telegram-update-voice-transcription-similar-channels-feature |access-date=17 December 2023 |website=The Verge |language=en}} as well as numerous other increases such as the number of pinned chats and folders. Premium users have access to extra stickers, emoji, reactions, and customization features like a special badge and the ability to change the look of their messages in chats. Premium users get access to additional settings, like instant chat translation, and the ability to restrict who can send them voice messages.{{Cite web |last=Singh |first=Manish |date=19 June 2022 |title=Telegram launches premium tier as it tops 700 million users |url=https://techcrunch.com/2022/06/19/telegram-tops-700-million-users-launches-premium-tier/ |access-date=5 December 2023 |website=TechCrunch |language=en-US}}{{Cite web |last=Roth |first=Emma |date=19 June 2022 |title=Telegram's Premium subscription is here and it costs $4.99 / month |url=https://www.theverge.com/2022/6/19/23174976/telegram-premium-subscription-4-99-month-bigger-uploads-faster-downloads |access-date=5 December 2023 |website=The Verge |language=en}}

As of 2023, Telegram Premium can be acquired via in-app purchases facilitated by Apple and Google, directly via Telegram's @PremiumBot, or with cryptocurrency on the Fragment platform.{{Cite web |date=2 August 2023 |title=What is Telegram Premium and should you upgrade? |url=https://www.androidauthority.com/telegram-premium-price-features-availability-3177921/ |access-date=5 December 2023 |website=Android Authority |language=en}} Users are able to purchase a subscription for themselves, or purchase a subscription for someone else to send as a gift. Premium subscriptions can also be won through official Channel Giveaways, in which Telegram channels pre-purchase a specific number of Premium subscriptions that are randomly given away to their subscribers.{{Cite web |last=Vasile |first=Cosmin |date=7 November 2023 |title=Telegram update brings the ability to host giveaways |url=https://www.phonearena.com/news/telegram-update-channel-giveaways_id152336 |access-date=5 December 2023 |website=PhoneArena |language=en-US}}

File:Telegra.ph example article editing.png

People can use their Telegram accounts to author articles on Telegraph – a minimalistic text editor and publisher. While articles on Telegraph can be published anonymously, tying them to one's account allows one to check their view count and edit them later. Telegraph natively supports Instant View, a feature which lets users read full articles in the chat with no load time and without opening an external browser.{{Cite web |date=23 November 2016 |title= Secure messaging app Telegram now offers its own anonymous blogging platform |url= https://techcrunch.com/2016/11/22/telegram-telegraph/ |url-status= live |archive-url=https://web.archive.org/web/20210525092951/https://techcrunch.com/2016/11/22/telegram-telegraph/ |archive-date=25 May 2021 |access-date= 25 May 2021 |work=TechCrunch}}{{Cite web |date=10 December 2018 |title=Custom Languages, Instant View 2.0 and More |url= https://telegram.org/blog/translations-iv2 |url-status=live |archive-url=https://web.archive.org/web/20201209081856/https://telegram.org/blog/translations-iv2 |archive-date=9 December 2020 |access-date=16 August 2020 | publisher =Telegram}}{{Cite web |title=Instant View |url= https://instantview.telegram.org/ |url-status= live |archive-url=https://web.archive.org/web/20201209081927/https://instantview.telegram.org/ |archive-date= 9 December 2020 |access-date=16 August 2020 | publisher = Telegram}}

When an article is first published, the URL is generated automatically from its title. Non-Latin characters are transliterated, spaces are replaced with hyphens, and the date of publication is added to the address. For example, an article titled "Telegraph (blog platform)" published on 17 November would receive the URL /Telegraph-blog-platform-11-17.

Text formatting options are also minimal: two levels of headings, single-level lists, bold, italics, quotes, and hyperlinks are supported. Authors could upload images and videos to the page, with a limit of 5 MB, however, it has been disabled since September 2024.{{Cite web |title=Du Rove's Channel |url=https://t.me/durov/343 |access-date=5 October 2024 |website=Telegram}} When an author adds links to YouTube, Vimeo, or Twitter, the service allows you to embed their content directly in the article.{{Cite web |date=22 November 2016 |title=Telegram launches Telegraph, a long-form publishing platform |url= https://venturebeat.com/2016/11/22/telegram-launches-telegraph-a-long-form-publishing-platform/ |url-status=live |archive-url=https://web.archive.org/web/20201209084752/https://venturebeat.com/2016/11/22/telegram-launches-telegraph-a-long-form-publishing-platform/ |archive-date=9 December 2020 |access-date=5 December 2020 |website=VentureBeat |language=en-US}}

In February 2018, Telegram launched their social login feature to its users, named Telegram Login. It features a website widget that could be embedded into websites, allowing users to sign into a third party website with their Telegram account. The gateway sends users' Telegram name, username, and profile picture to the website owner, while users' phone number remains hidden. The gateway is integrated with a bot, which is linked with the developer's specific website domain.{{Cite news |title=Telegram 4.8 arrives with Telegram Login and streaming |language=en |work=Neowin |url=https://www.neowin.net/news/telegram-48-arrives-with-telegram-login-and-streaming |url-status=live |access-date=12 February 2018 |archive-url=https://web.archive.org/web/20190518221145/https://www.neowin.net/news/telegram-48-arrives-with-telegram-login-and-streaming |archive-date=18 May 2019}}

In July 2018, Telegram introduced their online authorization and identity-management system, Telegram Passport, for platforms that require real-life identification.{{cite web |date=26 July 2018 |title=Introducing Telegram Passport |url=https://telegram.org/blog/passport |url-status= live |archive-url= https://web.archive.org/web/20201209121831/https://telegram.org/blog/passport |archive-date=9 December 2020 |access-date=4 August 2018 | publisher = Telegram}} It asks users to upload their own official documents such as passport, identity card, driver license, etc. When an online service requires such identification documents and verification, it forwards the information to the platform with the user's permission. Telegram stated that it does not have access to the data, while the platform will share the information only with the authorized recipient.{{Cite news |title=Telegram Passport stores your real-world IDs in the cloud |language=en-US |work=Engadget |url=https://www.engadget.com/2018/07/27/telegram-passport/ |url-status=live |access-date=4 August 2018 |archive-url=https://web.archive.org/web/20190724110556/https://www.engadget.com/2018/07/27/telegram-passport/ |archive-date= 24 July 2019}} However, the service was criticised for being vulnerable to online brute-force attacks.{{Cite news |last=Canellis |first= David |date= 2 August 2018 |title=Telegram Passport is already drawing fire for not being secure enough |language=en-US | work = The Next Web |url= https://thenextweb.com/hardfork/2018/08/02/telegram-passport-passwords-crack/ |url-status=live |access-date=4 August 2018 |archive-url= https://web.archive.org/web/20201209121912/https://thenextweb.com/hardfork/2018/08/02/telegram-passport-passwords-crack/ |archive-date=9 December 2020}}

In December 2020, Telegram launched a Bugs and Suggestions platform,{{Cite web | title=Telegram messenger launches voice chat for groups, to introduce premium features next year |url=https://telecom.economictimes.indiatimes.com/news/telegram-messenger-launches-voice-chat-for-groups-to-introduce-premium-features-next-year/79936124 |access-date=17 June 2023 |website=ETTelecom | via = India Times}} where users can submit bug reports and suggestion cards for new features. Others can then vote and comment on the cards.

In October 2024, Telegram launched a verification platform, called Telegram Gateway, allowing third-party services to authenticate their users by sending verification codes via Telegram.{{Cite web |last=Morales |first=James |date=15 October 2024 |title=Pavel Durov Introduces Telegram Phone Verification Service, Calls Price 'Unprecedentedly Low' |url=https://www.ccn.com/news/technology/pavel-durov-telegram-gateway-phone-verification/ |access-date=21 October 2024 |website=CCN}}

File:Explanation of secret chats (Telegram).png

For encrypted chats (branded as Secret Chats), Telegram uses a custom-built symmetric encryption scheme called MTProto. The protocol was developed by Nikolai Durov and other developers at Telegram and, as of version 2.0, is based on 256-bit symmetric AES encryption, 2048-bit RSA encryption and Diffie–Hellman key exchange.{{cite web|url = https://core.telegram.org/techfaq|title = FAQ for the Technically Inclined|website = Telegram|access-date = 9 January 2016|archive-date = 28 January 2017|archive-url = https://web.archive.org/web/20170128144833/https://core.telegram.org/techfaq|url-status = live}}{{Cite arXiv |last1=Miculan |first1=Marino |last2=Vitacolonna |first2=Nicola |date=5 December 2020 |title=Automated Symbolic Verification of Telegram's MTProto 2.0 |class=cs.CR |eprint=2012.03141v1 }}

MTProto 1.0 was deprecated in favor of MTProto 2.0 in December 2017, which was deployed in Telegram clients as of v4.6.

Version 2.0 was proven formally correct in December 2020 by a team from the University of Udine, Italy. The team reviewed the protocol after realizing that they could only find in-depth verifications done of version 1.0, where most criticisms were levied. They used ProVerif, a verifier based on the symbolic Dolev-Yao model. In the published paper, they "provide a fully automated proof of the soundness of MTProto 2.0’s protocols for authentication, normal chat, end-to-end encrypted chat, and re-keying mechanisms with respect to several security properties, including authentication, integrity, confidentiality and perfect forward secrecy...MTProto 2.0 is assumed to be a perfect authenticated encryption scheme (IND-CCA and INT-CTXT)."{{cite journal |last1=Miculan |first1=Marino |last2=Vitacolonna |first2=Nicola |title=Automated verification of Telegram's MTProto 2.0 in the symbolic model |journal=Computers & Security |date=March 2023 |volume=126 |pages=103072 |doi=10.1016/j.cose.2022.103072}}

However, the team also stated that because all communication, including plaintext and ciphertext, passes through Telegram servers, and because the server is responsible for choosing Diffie–Hellman parameters, the "server should not be considered as trusted." They also concluded that a man-in-the-middle attack is possible if users fail to check the fingerprints of their shared keys. Finally, they qualified their conclusion with the caveat that "properties need to be formally proved in order to deem MTProto 2.0 definitely secure. This proof cannot be done in a symbolic model like ProVerif's, but it can be achieved in a computational model, using tools like CryptoVerif or EasyCrypt."

As with most instant messaging protocols, apart from XMPP, Telegram uses centralized servers. Telegram Messenger LLP has servers in a number of countries throughout the world to improve the response time of their service.{{cite web|trans-title=Telegram, the chat that competes with WhatsApp|place=UY|url=http://www.elpais.com.uy/vida-actual/que-telegram-chat-que-compite.html|work=El País|title=Telegram, el chat que compite con Whatsapp|language=es|access-date=8 January 2016|archive-date=8 February 2014|archive-url=https://web.archive.org/web/20140208163824/http://www.elpais.com.uy/vida-actual/que-telegram-chat-que-compite.html|url-status=live}} Telegram's server-side software is closed-source and proprietary.{{Cite web|title=Telegram FAQ|url=https://telegram.org/faq#q-can-i-get-telegram-39s-server-side-code|access-date=29 March 2021|website=Telegram|archive-date=9 February 2014|archive-url=https://web.archive.org/web/20140209082001/https://telegram.org/faq#q-can-i-get-telegram-39s-server-side-code|url-status=live}} Pavel Durov said that it would require a major architectural redesign of the server-side software to connect independent servers to the Telegram cloud.{{cite web|title = Pavel Durov, creador de Telegram: "Ninguna aplicación es 100% segura"|url = http://www.eldiario.es/turing/moviles_y_tabletas/telegram-pavel_durov-entrevista-app-movil-seguridad_0_224677688.html|work = eldiario.es|date = 2 February 2014|access-date = 12 February 2014|trans-title = Pavel Durov, creator of Telegram: "No application is 100% safe"|last = Rull|first = Antonio|language = es|archive-date = 8 February 2014|archive-url = https://web.archive.org/web/20140208003046/http://www.eldiario.es/turing/moviles_y_tabletas/telegram-pavel_durov-entrevista-app-movil-seguridad_0_224677688.html|url-status = live}}

For users who signed in from the European Economic Area (EEA) or United Kingdom, the General Data Protection Regulations (GDPR) are supported by storing data only on servers in the Netherlands, and designating a London-based company as their responsible data controller.{{cite web |url=https://www.lexology.com/library/detail.aspx?g=066cf923-6cb5-49d9-b0c7-2c433ba521ea |title=GDPR vs US Discovery: US Court Makes Clear Non-US Entities Can't Avoid Discovery |publisher=Law Business Research |work=Linklaters LLP |date=29 January 2020 |access-date=19 June 2020 |archive-date=21 June 2020 |archive-url=https://web.archive.org/web/20200621042801/https://www.lexology.com/library/detail.aspx?g=066cf923-6cb5-49d9-b0c7-2c433ba521ea |url-status=live }}{{cite web |url=https://telegram.org/privacy#4-1-storing-data |title=Telegram Privacy Policy – Storing Data |publisher=Telegram |access-date=19 June 2020 |archive-date=8 September 2015 |archive-url=https://web.archive.org/web/20150908095619/https://telegram.org/privacy#4-1-storing-data |url-status=live }}{{cite web |url=https://telegram.org/privacy#1-4-eea-representative |title=Telegram Privacy Policy – EEA Representative |publisher=Telegram |access-date=19 June 2020 |archive-date=8 September 2015 |archive-url=https://web.archive.org/web/20150908095619/https://telegram.org/privacy#1-4-eea-representative |url-status=live }}

Telegram has various client apps, some developed by Telegram Messenger LLP and some by the community. Most of them are free and open-source and released under the GNU General Public Licence {{Nowrap|version 2}} or 3. The official clients support sending any file format extensions. The built-in media viewer supports common media formats – JPEG, PNG, WebP for images and H.264 and HEVC in videos in MP4 container and MP3, FLAC, Vorbis, Opus and AAC for audio.

In 2021, the Telegram team announced a direct build of its Android app. Telegram for Android is available directly from the Telegram website.{{Cite web|title=Telegram for Android|url=https://telegram.org/android|access-date=17 June 2021|website=Telegram|archive-date=14 June 2021|archive-url=https://web.archive.org/web/20210614012044/https://telegram.org/android|url-status=live}} It is automatically updated and will most likely get new versions faster than the apps in the Play Store and App Store.{{Cite web|title=Telegram Tips|url=https://t.me/TelegramTips/275|access-date=17 June 2021|website=Telegram|archive-date=24 June 2021|archive-url=https://web.archive.org/web/20210624200141/https://t.me/TelegramTips/275|url-status=live}} A distinctive feature of this version is the ability to view channels/groups on a specific topic without censorship, which cannot be viewed from an app distributed from Google Play or the Apple Store due to their policies.{{Citation needed|date=June 2021}}

Common specifications:

• No cloud backup option for secret chat

Telegram has public APIs with which developers can access the same functionality as Telegram's official apps to build their own instant messaging applications.{{Cite news|url=http://www.programmableweb.com/news/can-telegram-beat-whatsapp-public-api/2014/03/03|title=Can Telegram Beat WhatsApp with a Public API?|last=Roble|first=Patricio|date=3 March 2014|work=ProgrammableWeb|access-date=17 March 2016|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512230512/https://www.programmableweb.com/news/can-telegram-beat-whatsapp-public-api/2014/03/03|url-status=live}} In February 2015, creators of the unofficial WhatsApp+ client released the Telegram Plus app, later renamed to Plus Messenger, after their original project got a cease-and-desist order from WhatsApp.{{Cite news|url=http://www.androidpolice.com/2015/02/27/whatsapp-developer-releases-telegram-forced-drop-first-project/|title=WhatsApp+ Developer Releases Telegram+ After Being Forced To Drop The First Project|last=King|first=Bertel|date=27 February 2015|work=AndroidPolice|access-date=17 March 2016|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512230458/https://www.androidpolice.com/2015/02/27/whatsapp-developer-releases-telegram-forced-drop-first-project/|url-status=live}}{{cite web|url=http://www.androidpolice.com/2015/01/21/whatsapp-now-officially-dead-receiving-cease-desist-real-whatsapp/|title=WhatsApp+ Is Now Officially Dead After Receiving A Cease And Desist From The Real WhatsApp|date=21 January 2015|website=Android Police|access-date=17 March 2016|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512230511/https://www.androidpolice.com/2015/01/21/whatsapp-now-officially-dead-receiving-cease-desist-real-whatsapp/|url-status=live}} In September 2015, Samsung released a messaging application based on these APIs.{{cite web|url = http://news.samsung.com/global/socializer-messenger-app-offers-a-new-approach-to-messaging|title = Socializer Messenger App Offers a New Approach to Messaging|date = 14 September 2015|access-date = 3 January 2016|archive-date = 12 May 2019|archive-url = https://web.archive.org/web/20190512230453/https://news.samsung.com/global/socializer-messenger-app-offers-a-new-approach-to-messaging|url-status = live}}

Telegram also offers an API that allows developers to create bots, which are accounts controlled by programs.{{cite web|url=http://www.programmableweb.com/news/telegram-launches-bot-api-and-platform/2015/06/29|title=Telegram Launches Bot API and Platform|last=Carter|first=Eric|date=27 June 2015|website=ProgrammableWeb|access-date=17 March 2016|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512230507/https://www.programmableweb.com/news/telegram-launches-bot-api-and-platform/2015/06/29|url-status=live}}{{cite web|url=https://techcrunch.com/2015/06/24/telegrams-new-platform-lets-developers-create-smart-message-bots-with-multiple-uses/|title=Telegram's New Platform Lets Developers Create Smart Message Bots With Multiple Uses|last=Butcher|first=Mike|date=24 June 2015|website=TechCrunch|access-date=15 September 2017|archive-date=3 May 2019|archive-url=https://web.archive.org/web/20190503201134/https://techcrunch.com/2015/06/24/telegrams-new-platform-lets-developers-create-smart-message-bots-with-multiple-uses/|url-status=live}} Such bots are used, among other things, to emulate and play old games in the app and inform users about vaccine availability for COVID-19.{{cite web |url=https://jilaxzone.com/2021/03/12/theres-retro-game-emulator-hiding-inside-telegram-messenger-heres-how-to-use-it-android-iphone/ |title=There's retro-game emulator hiding inside Telegram Messenger. Here's how to use it |last=Jilaxzone |first=Jonathan |date=12 March 2021 |website=Jilaxzone |access-date=14 May 2021 |archive-date=14 May 2021 |archive-url=https://web.archive.org/web/20210514230822/https://jilaxzone.com/2021/03/12/theres-retro-game-emulator-hiding-inside-telegram-messenger-heres-how-to-use-it-android-iphone/ |url-status=live }}{{cite web |url=https://www.nbcbayarea.com/news/local/eligible-but-struggling-to-get-a-covid-19-vaccine-appointment-here-are-some-tips/2506408/ |title=Eligible But Struggling to Get a COVID-19 Vaccine Appointment? Here Are Some Tips |last=Budman |first=Scott |date=30 March 2021 |website=NBC Bay Area |access-date=14 May 2021 |archive-date=14 May 2021 |archive-url=https://web.archive.org/web/20210514230822/https://www.nbcbayarea.com/news/local/eligible-but-struggling-to-get-a-covid-19-vaccine-appointment-here-are-some-tips/2506408/ |url-status=live }}

In addition, Telegram offers functions for making payments directly within the platform, alongside an external service such as Stripe.

In 2025, xAI signed a $300mln program with Telegram for Grok to provide full functions within Telegram. {{Cite news |date=2025-05-28 |title=Telegram, Musk-owned xAI partner to distribute Grok to messaging app's users |url=https://www.reuters.com/business/telegram-musks-xai-partner-distribute-grok-messaging-apps-users-2025-05-28/ |access-date=2025-06-08 |work=Reuters |language=en}}{{cite web | url=https://www.cnbc.com/amp/2025/05/28/elon-musk-xai-telegram-grok.html | title=Telegram CEO announces $300 million partnership with Elon Musk's xAI and Grok | work=CNBC | last1=Capoot | first1=Ashley }} The amount was paid using a combination of cash and xAI equity.{{Cite web |last=Durov |first=Pavel |title=https://x.com/durov/status/1927703704863465953 |url=https://x.com/durov/status/1927703704863465953 |url-status=live |archive-url=http://web.archive.org/web/20250528163939/https://x.com/durov/status/1927703704863465953 |archive-date=2025-05-28 |access-date=2025-06-08 |website=X (formerly Twitter) |language=en}}

The company was initially supported by founding CEO Pavel Durov's personal funds after the sale of his stake in VK. In January 2018, it launched a private placement and collected $1.7 billion from investors such as Kleiner Perkins, Sequoia Capital, and Benchmark.{{cite news |first1=Chloe |last1=Cornish |first2=Richard |last2=Waters |title=Silicon Valley investors line up to back Telegram ICO |url=https://www.ft.com/content/790d9506-0175-11e8-9650-9c0ad2d7c5b5 |website=Financial Times |date=25 January 2018 |access-date=28 September 2021 |url-access=subscription |archive-date=28 September 2021 |archive-url=https://web.archive.org/web/20210928082709/https://www.ft.com/content/790d9506-0175-11e8-9650-9c0ad2d7c5b5 |url-status=live }} After the shutdown of the TON project, the company needed to repay the investors the money that was not spent on its development during 2018 and the beginning of 2019, while the project was active.{{Cite news |last=Schechner |first=Sam |date=15 March 2021 |title=Telegram App Is Booming but Needs Advertisers—and $700 Million Soon |language=en-US |work=The Wall Street Journal |url=https://www.wsj.com/articles/telegram-app-is-booming-but-needs-advertisersand-700-million-soon-11615806001 |access-date=16 March 2021 |issn=0099-9660 |archive-date=16 March 2021 |archive-url=https://web.archive.org/web/20210316153024/https://www.wsj.com/articles/telegram-app-is-booming-but-needs-advertisersand-700-million-soon-11615806001 |url-status=live }}

On 15 March 2021, Telegram conducted a five-year public bonds placement worth $1 billion. The funding was required to cover the debts amounting to $625.7 million, including $433 million to investors who bought futures for Gram tokens in 2018 and included purchasers such as David Yakobashvili.{{cite web |url=https://www.rbc.ru/finances/15/03/2021/604f11019a794780341309c9 |title=Telegram разместил бонды на $1 млрд. На каких условиях инвесторы рискнули вложиться во внебиржевые бумаги |author1=Павел Казарновский|author2=Владислав Скобелев|author3=Анна Балашова |date=15 March 2021 |publisher=RBC |access-date=15 March 2021 |archive-date=15 March 2021 |archive-url=https://web.archive.org/web/20210315144542/https://www.rbc.ru/finances/15/03/2021/604f11019a794780341309c9 |url-status=live }} On 23 March, Telegram sold additional bonds worth $150 million to the Abu Dhabi Mubadala Investment Company and Abu Dhabi Catalyst Partners.{{cite web|author=Natasha Lomas|date=23 March 2021|title=Telegram raises $150M from Mubadala and Abu Dhabi CP via pre-IPO convertible bonds|url=https://techcrunch.com/2021/03/23/telegram-raises-150m-from-mubadala-and-abu-dhabi-cp-via-pre-ipo-convertible-bonds/|access-date=23 March 2021|publisher=TechCrunch|archive-date=23 March 2021|archive-url=https://web.archive.org/web/20210323132059/https://techcrunch.com/2021/03/23/telegram-raises-150m-from-mubadala-and-abu-dhabi-cp-via-pre-ipo-convertible-bonds/|url-status=live}}

A day later, the Mubadala Investment Company stated that Russia's sovereign wealth fund participated in its deal undisclosed through the Russia-UAE joint investment platform to buy convertible bonds. A Telegram spokesperson stated: "RDIF is not in the list of investors we sold bonds to. We wouldn't be open to any transaction with this fund" and "[t]he funds that did invest, including Mubadala, confirmed to us that RDIF was not among their LPs [limited partners]."{{cite web|author=Jake Rudnitsky, Zainab Fattah|date=23 March 2021|title=Mubadala Says It Brought RDIF Into Telegram Bond Stake|url=https://www.bloombergquint.com/business/russia-mubadala-invest-in-telegram-after-kremlin-ban-failed|access-date=3 April 2021|publisher=Bloomberg|archive-date=25 March 2021|archive-url=https://web.archive.org/web/20210325050817/https://www.bloombergquint.com/business/russia-mubadala-invest-in-telegram-after-kremlin-ban-failed|url-status=live}} According to the contract, the holders of the bonds will be provided with an option to convert them to shares at a 10% discount if the company conducts an open IPO.

Durov stated that the move aimed to "enable Telegram to continue growing globally while sticking to its values and remaining independent". According to press reports, prior to the bonds placement, Durov had rejected an investment offer for a 5–10% stake in the company as well as several undisclosed ones, valuing the company in a $30–40 billion range. In March 2024, Telegram sold an additional $330 million in bonds. Durov said the bond sale "will further solidify our position as an independent platform that is able to challenge the 'Goliaths' of our industry".{{cite web|url=https://www.reuters.com/technology/telegram-secures-330-million-bond-sales-2024-03-18/|title=Telegram secures $330 million in bond sales|author=Harshita Mary Varghese|date=18 March 2024|publisher=Reuters|access-date=18 March 2024}}

Telegram has stated that the company will never serve advertisements in private chats.{{cite web |url=https://dollarsandsense.sg/how-whatsapp-telegram-snapchat-make-money-why-you-should-care/ |title=How Does WhatsApp, Telegram And Snapchat Make Money? (And Why You Should Care) |author=Tao Ming Hui |date=16 November 2017 |publisher=Dollars and Sense |access-date=10 March 2021 |archive-date=13 September 2019 |archive-url=https://web.archive.org/web/20190913105808/http://dollarsandsense.sg/how-whatsapp-telegram-snapchat-make-money-why-you-should-care/ |url-status=live }} In late 2020, Durov announced that the company was working on its own ad platform, and would integrate non-targeted ads in public one-to-many channels, that already were selling and displaying ads in the form of regular messages.{{Cite web|url=https://techcrunch.com/2020/12/23/telegram-to-launch-an-ad-platform-as-it-approaches-500-million-users/|title=Telegram, nearing 500 million users, to begin monetizing the app|date=23 December 2020 |access-date=20 January 2021|archive-date=27 June 2021|archive-url=https://web.archive.org/web/20210627152101/https://techcrunch.com/2020/12/23/telegram-to-launch-an-ad-platform-as-it-approaches-500-million-users/|url-status=live}} Ads from Telegram's "Sponsored Messages" platform began to appear in channels with more than 1000 followers in October 2021.

In late 2020, Durov announced that Telegram will consider adding paid features aimed at enterprise clients. According to him, these features will require more bandwidth and the added cost will be covered by the feature prices, in addition to covering some of the costs incurred by regular users.{{Cite web|url=https://gadgets.ndtv.com/apps/news/telegram-private-messaging-app-500-million-users-premium-subscription-2021-pavel-durov-2342668|title= Telegram to Launch Paid Features for Business and Power Users in 2021 |date=23 December 2020 |access-date=31 May 2021}}

In June 2024, Telegram launched Telegram Stars to facilitate in-app purchases of digital goods and services, in compliance with policies from the App Store and Play Store.{{Cite web |date=2024-06-06 |title=Telegram Stars: Pay for Digital Goods and More |url=https://telegram.org/blog/telegram-stars#ready-for-app-stores |access-date=2025-01-10 |website=Telegram}} Following the launch of Stars, Telegram released several updates to their functionality, such as allowing Stars to be used to unlock media in channels or to buy gifts for other users.{{Cite web |last=Hearn |first=Patrick |date=2025-01-02 |title=Telegram's first update of 2025 adds NFTs and more message reactions |url=https://www.androidpolice.com/telegram-update-collectible-gifts-nfts-service-message-reactions/ |access-date=2025-01-10 |website=Android Police |language=en}}

In December 2024, Telegram CEO Pavel Durov announced that Telegram had reached profitability, due to significant growth in Premium subscriptions and Telegram ad sales, assisted by the other monetization features launched throughout 2024.{{Cite web |last=Mehta |first=Ivan |date=23 December 2024 |title=Pavel Durov says Telegram is now profitable |url=https://techcrunch.com/2024/12/23/pavel-durov-says-telegram-is-now-profitable/ |access-date=23 December 2024 |website=TechCrunch |language=en-US}}

{{Main|The Open Network}}

In 2017, in an attempt to monetize Telegram without advertising, the company began the development of a blockchain platform dubbed either "The Open Network" or "Telegram Open Network" (TON) and its native cryptocurrency "Gram". The project was announced in mid-December 2017{{cite web |url=https://www.bloombergquint.com/technology/cryptic-russian-crusader-says-his-5-billion-app-can-t-be-bought |title=This $5 Billion Encrypted App Isn't for Sale at Any Price |author1=Stepan Kravchenko|author2=((Nour Al Ali))|author3=Ilya Khrennikov |date=11 December 2017 |publisher=Bloomberg |access-date=8 March 2021 |archive-date=27 June 2021 |archive-url=https://web.archive.org/web/20210627152101/https://www.bloombergquint.com/technology/cryptic-russian-crusader-says-his-5-billion-app-can-t-be-bought |url-status=live }} and its 132-page technical paper became available in January 2018.{{cite web|url=https://drive.google.com/file/d/1ucUeKg_NiR8RxNAonb8Q55jZha03WC0O/view|title=TON.pdf|website=Google Docs|access-date=5 May 2018|archive-date=27 August 2018|archive-url=https://web.archive.org/web/20180827165521/https://drive.google.com/file/d/1ucUeKg_NiR8RxNAonb8Q55jZha03WC0O/view|url-status=live}} The codebase behind TON was developed by Pavel Durov's brother Nikolai Durov, the core developer of Telegram's MTProto protocol.{{cite web |url=https://coinpost.media/f/telegram-ton/ |title=Telegram TON (Telegram Open Network) |publisher=Coinpost |access-date=23 March 2021 |archive-date=3 March 2021 |archive-url=https://web.archive.org/web/20210303112734/https://coinpost.media/f/telegram-ton/ |url-status=live }} In January 2018, a 23-page white paper and a detailed 132-page technical paper for TON blockchain became available.{{cite web |url=https://sports.yahoo.com/telegram-privacy-focused-user-could-180800518.html |title=Telegram's Privacy-Focused User Base Could Become TON Blockchain's Killer App |date=10 January 2018 |publisher=Bitcoin Magazine |access-date=23 March 2021 |archive-date=27 June 2021 |archive-url=https://web.archive.org/web/20210627152102/https://sports.yahoo.com/telegram-privacy-focused-user-could-180800518.html |url-status=live }}

Durov planned to power TON with the existing Telegram user base, and turn it into the largest blockchain and a platform for apps and services akin to a decentralized WeChat, Google Play, and App Store.{{cite web |url=https://techcrunch.com/2018/01/08/telegram-open-network/ |title=Telegram plans multi-billion dollar ICO for chat cryptocurrency |author=Mike Butcher, Josh Konstine |date=8 January 2018 |publisher=TechCrunch |access-date=4 April 2020 |archive-date=23 November 2020 |archive-url=https://web.archive.org/web/20201123181319/https://techcrunch.com/2018/01/08/telegram-open-network/ |url-status=live }}{{cite web |url=https://techcrunch.com/2018/01/15/inside-telegrams-ambitious-1-2b-ico-to-create-the-next-ethereum/ |title=Inside Telegram's ambitious $1.2B ICO to create the next Ethereum |author=Jon Russel |date=15 January 2018 |publisher=TechCrunch |access-date=4 April 2020 |archive-date=3 April 2020 |archive-url=https://web.archive.org/web/20200403222412/https://techcrunch.com/2018/01/15/inside-telegrams-ambitious-1-2b-ico-to-create-the-next-ethereum/ |url-status=live }} Besides, the TON had the potential to become a decentralized alternative to Visa and MasterCard due to its ability to scale and support millions of transactions per second.{{cite web |url=https://www.rbth.com/science-and-tech/331547-durov-vk-telegram-russia-networks |title=Telegram's Pavel Durov in court over his quest to revolutionize cryptocurrency |author=Josh Nadeau |date=15 January 2020 |publisher=Russia Beyond The Headlines |access-date=4 April 2020 |archive-date=28 February 2020 |archive-url=https://web.archive.org/web/20200228030201/https://www.rbth.com/science-and-tech/331547-durov-vk-telegram-russia-networks |url-status=live }} In January and February 2018, the company ran a private sale of futures contracts for Grams,{{Cite news|url=https://thenextweb.com/hardfork/2018/01/09/telegram-ico-white-paper-leak|title=Here is the leaked white paper for the massive Telegram ICO|last=Mix|work=HardFork|access-date=6 April 2018|language=en-US|archive-date=9 November 2020|archive-url=https://web.archive.org/web/20201109043158/https://thenextweb.com/hardfork/2018/01/09/telegram-ico-white-paper-leak/|url-status=live}} raising around $1.7 billion.{{cite web|url=http://www.cnews.ru/news/top/2018-04-02_pri_kakih_usloviyah_telegram_vernet_investoram|title=Under what conditions will Telegram return to investors the collected $ 2.55 billion|last1=Korolev|first1=Igor|date=2 April 2018|website=CNews|language=ru|access-date=12 October 2018|archive-date=23 November 2020|archive-url=https://web.archive.org/web/20201123182731/https://www.cnews.ru/news/top/2018-04-02_pri_kakih_usloviyah_telegram_vernet_investoram|url-status=live}}{{cite web|url=https://www.theverge.com/2018/4/1/17186004/telegram-presale-open-network-app-ico-cryptocurrency-ton|title=Telegram has raised a total of $1.7 billion from its two pre-ICO sales|last1=Liptak|first1=Andrew|date=1 April 2018|website=The Verge|access-date=12 October 2018|archive-date=9 November 2020|archive-url=https://web.archive.org/web/20201109011226/https://www.theverge.com/2018/4/1/17186004/telegram-presale-open-network-app-ico-cryptocurrency-ton|url-status=live}}{{cite news|url=http://fortune.com/2018/03/30/bitcoin-price-telegram-ico-presale/|title=Even as Bitcoin Languishes, Telegram Raises $1.7 Billion Ahead of Largest ICO Ever|last1=Shen|first1=Lucinda|date=31 March 2018|access-date=31 March 2018|publisher=Fortune|archive-date=9 November 2020|archive-url=https://web.archive.org/web/20201109032339/https://fortune.com/2018/03/30/bitcoin-price-telegram-ico-presale/|url-status=live}}{{Cite news|url=https://www.crowdfundinsider.com/2018/04/131248-telegram-files-new-form-d-with-sec-indicating-1-7-billion-will-be-raised/|title=Telegram Files New Form D with SEC Indicating $1.7 Billion will be Raised {{!}} Crowdfund Insider|date=2 April 2018|work=Crowdfund Insider|access-date=6 April 2018|language=en-US|archive-date=30 October 2020|archive-url=https://web.archive.org/web/20201030112035/https://www.crowdfundinsider.com/2018/04/131248-telegram-files-new-form-d-with-sec-indicating-1-7-billion-will-be-raised/|url-status=live}} No public offering took place.{{Cite news|url=https://www.wsj.com/articles/telegram-messaging-app-scraps-plans-for-public-coin-offering-1525281933?ns=prod/accounts-wsj|title=Telegram Messaging App Scraps Plans for Public Coin Offering|last=Vigna|first=Paul|date=2 May 2018|work=The Wall Street Journal|access-date=11 November 2018|language=en-US|archive-date=12 November 2018|archive-url=https://web.archive.org/web/20181112021355/https://www.wsj.com/articles/telegram-messaging-app-scraps-plans-for-public-coin-offering-1525281933?ns=prod%2Faccounts-wsj|url-status=live}}

The development of TON took place in a completely isolated manner, and the release was postponed several times. The test network was launched in January 2019.{{cite web |url=https://thebell.io/en/despite-delay-durov-on-track-to-launch-his-cryptocurrency-in-march/ |title=Despite delay, Durov on track to launch his cryptocurrency in March |date=23 January 2019 |publisher=The Bell |access-date=17 March 2021 |archive-date=13 February 2021 |archive-url=https://web.archive.org/web/20210213105104/https://thebell.io/en/despite-delay-durov-on-track-to-launch-his-cryptocurrency-in-march/ |url-status=live }} The launch of the TON main network was scheduled for 31 October.{{cite web |url=https://www.theverge.com/2019/8/27/20835987/telegram-gram-cryptocurrency-coin-october-31-deadline-ico |title=Telegram will launch its Gram cryptocurrency by October 31 or bust |author=Sean Hollister |date=27 August 2019 |publisher=The Verge |access-date=21 March 2021 |archive-date=8 November 2020 |archive-url=https://web.archive.org/web/20201108003953/https://www.theverge.com/2019/8/27/20835987/telegram-gram-cryptocurrency-coin-october-31-deadline-ico |url-status=live }} On 30 October, the U.S. Securities and Exchange Commission obtained a temporary restrictive order to prevent the distribution of Grams to initial purchasers; the regulator considered the legal scheme employed by Telegram as an unregistered securities offering with initial buyers acting as underwriters.{{cite web |url=https://www.nortonrosefulbright.com/-/media/files/nrf/nrfweb/knowledge-pdfs/a-telegram-to-safts-beware.pdf |title=Blockchain law. A "Telegram" to SAFTs: "Beware!" |author=Robert A. Schwinger |date=26 May 2020 |publisher=New York Law Journal |access-date=15 March 2021 |archive-date=27 June 2021 |archive-url=https://web.archive.org/web/20210627152102/https://www.nortonrosefulbright.com/-/media/files/nrf/nrfweb/knowledge-pdfs/a-telegram-to-safts-beware.pdf |url-status=live }}

The judge hearing the Telegram v. SEC case, P. Kevin Castel, ultimately agreed with the SEC's argument{{cite web|title=Cooley|url=https://www.cooley.com/news/insight/2020/2020-05-07-sec-v-telegram-key-takeaways-implications|website=www.cooley.com|access-date=13 May 2020|archive-date=24 August 2020|archive-url=https://web.archive.org/web/20200824212924/https://www.cooley.com/news/insight/2020/2020-05-07-sec-v-telegram-key-takeaways-implications|url-status=live}} and kept the restrictions on Gram distribution in force. The ban applied to non-U.S.-based purchasers as well, because Telegram could not prevent the re-sale of Grams to U.S. citizens on a secondary market, as the anonymity of users was one of the key features of TON.{{cite web |url=https://www.jdsupra.com/legalnews/is-there-life-for-safts-after-the-54728/ |title=Is There Life for SAFTs After the Telegram Case? |date=21 July 2020 |publisher=JD Supra |access-date=10 March 2021 |archive-date=7 September 2020 |archive-url=https://web.archive.org/web/20200907174839/https://www.jdsupra.com/legalnews/is-there-life-for-safts-after-the-54728/ |url-status=live }}{{cite web |url=https://www.gtlaw.com/en/insights/2020/4/sec-v-telegram--a-groundbreaking-decision-in-cryptocurrency-enforcement |title=SEC v. Telegram: A Groundbreaking Decision in Cryptocurrency Enforcement? |author=David I. Miller, Charlie Berk |date=1 April 2020 |publisher=Greenberg Traurig |access-date=10 March 2021 |archive-date=17 January 2021 |archive-url=https://web.archive.org/web/20210117023653/https://www.gtlaw.com/en/insights/2020/4/sec-v-telegram--a-groundbreaking-decision-in-cryptocurrency-enforcement |url-status=live }}{{cite web |url=https://www.nortonrosefulbright.com/-/media/files/nrf/nrfweb/knowledge-pdfs/a-telegram-to-safts-beware.pdf |title=Blockchain law. A "Telegram" to SAFTs: "Beware!" |author=Robert A. Schwinger |date=26 May 2020 |publisher=New York Law Journal |access-date=10 March 2021 |archive-date=27 June 2021 |archive-url=https://web.archive.org/web/20210627152102/https://www.nortonrosefulbright.com/-/media/files/nrf/nrfweb/knowledge-pdfs/a-telegram-to-safts-beware.pdf |url-status=live }} Following that, Durov announced the end of Telegram's active involvement with TON. On 26 June, the judge approved the settlement between Telegram and SEC. The company agreed to pay an $18.5 million penalty and return $1.22 billion to Gram purchasers.{{cite news |title=Telegram to pay SEC fine of $18.5 million and return $1.2 billion to investors as it dissolves TON |url=https://techcrunch.com/2020/06/26/telegram-to-pay-sec-fine-of-18-5-million-and-return-1-2-billion-to-investors-as-it-dissolves-ton/ |access-date=28 June 2020 |publisher=Techcrunch |date=26 June 2020 |archive-date=27 June 2020 |archive-url=https://web.archive.org/web/20200627223615/https://techcrunch.com/2020/06/26/telegram-to-pay-sec-fine-of-18-5-million-and-return-1-2-billion-to-investors-as-it-dissolves-ton/ |url-status=live }} In March 2021, Telegram launched a bonds offering to cover the debt and fund further growth of the app.{{Cite news|last=Schechner|first=Sam|date=15 March 2021|title=Telegram App Is Booming but Needs Advertisers—and $700 Million Soon|language=en-US|work=The Wall Street Journal|url=https://www.wsj.com/articles/telegram-app-is-booming-but-needs-advertisersand-700-million-soon-11615806001|access-date=16 March 2021|issn=0099-9660|archive-date=16 March 2021|archive-url=https://web.archive.org/web/20210316153024/https://www.wsj.com/articles/telegram-app-is-booming-but-needs-advertisersand-700-million-soon-11615806001|url-status=live}}

Due to Telegram's mixed nature as both a private communication method and a social media-like platform with mass groups and channels, along with its minimal restrictions on content with only calls to violence, illegal forms of pornography{{Cite magazine |last=Loucaides |first=Darren |date=8 February 2022 |title=How Telegram Became the Anti-Facebook |magazine=Wired |url=https://www.wired.com/story/how-telegram-became-anti-facebook/ |access-date=28 March 2022}} and scamming forbidden, the platform has been used by organizations and large groups for recruitment and spreading of their agenda. Organized use of the app has been linked to pro-democracy protests in Belarus,{{cite magazine |last1=Williams |first1=Sean |title=Belarus has torn up the protest rulebook. Everyone should listen |url=https://www.wired.co.uk/article/belarus-protests-telegram |magazine=Wired |access-date=19 April 2024}} Russia,{{cite web |title=Russia internet freedom: Mass rally in Moscow against Telegram ban |url=https://www.bbc.com/news/world-europe-43948618 |website=BBC |access-date=19 April 2024 |date=30 April 2018}} Hong Kong{{cite web |last1=Schectman |first1=Joel |title=Exclusive: Messaging app Telegram moves to protect identity of Hong Kong protesters |url=https://www.reuters.com/article/us-hongkong-telegram-exclusive/exclusive-messaging-app-telegram-moves-to-protect-identity-of-hong-kong-protesters-idUSKCN1VK2NI |website=Reuters |date=31 August 2019 |access-date=19 April 2024}} and Iran,{{cite news |last1=Woo |first1=Sam Schechner and Stu |title=Iranians Turn to Telegram App Amid Protests |url=https://www.wsj.com/articles/iranians-turn-to-telegram-app-amid-protests-1514919114 |website=WSJ}} as well as to the dissemination of state propaganda and violent rhetoric in oppressive regimes, the promotion of extremist views, and the digitalization of services provided by government entities and private businesses.{{cite web |title=Минфин запустил Телеграм-бот для упрощения процесса получения материальной помощи и пособия на ребенка |url=https://podrobno.uz/cat/obchestvo/minfin-zapustil-telegram-bot-dlya-uproshcheniya-protsessa-poluchenie-materialnoy-pomoshchi-i-posobiya/ |website=Podrobno.uz |access-date=19 April 2024 |language=ru}}{{cite web |title=SE "Medical Procurement of Ukraine" launched the Telegram chat-bot |url=https://medzakupivli.com/en/pro-mzu-eng/novini-eng/667-dp-medzakupivli-ukrainy-zapustylo-chat-bot-na-bazi-mesendzhera-telegram-2 |website=medzakupivli.com |access-date=19 April 2024 |language=en-gb |date=27 April 2021}}{{cite web |last1=Mae Soco |first1=Rhea |title=Chatbot launched as part of 'back to school' campaign - Khmer Times |url=https://www.khmertimeskh.com/50814827/chatbot-launched-as-part-of-back-to-school-campaign |website=Khmer Times |access-date=19 April 2024 |date=16 February 2021}}{{cite web |last1=Paul |first1=Andrew |title=Indonesia activates a disaster-relief chatbot after destructive floods |url=https://www.popsci.com/technology/chatbot-monsoons-humanitarian-indonesia/ |website=Popular Science |access-date=19 April 2024 |date=31 January 2023}}{{cite web |title=Usuarios del Transantiago podrán saber cuándo viene su bus a través de Facebook y Telegram |url=https://www.t13.cl/noticia/nacional/usuarios-del-transantiago-podran-saber-cuando-viene-su-bus-traves-facebook-y-telegram |website=www.t13.cl |date=23 June 2017 |access-date=19 April 2024}}{{cite web |last1=Salute |first1=Ministero della |title=Covid-19, nasce il canale Telegram del ministero della Salute |url=https://www.salute.gov.it/portale/news/p3_2_1_1_1.jsp?lingua=italiano&menu=notizie&p=null&id=4479 |website=www.salute.gov.it |language=IT}}

The app has been criticized by numerous research institutions and internet monitoring bodies due to violent organizations like ISIS, Proud Boys{{cite web|website=The New York Times|title=Proud Boys celebrate Trump's 'stand by' remark about them at the debate|date=29 September 2020|access-date=11 October 2020|url=https://www.nytimes.com/2020/09/29/us/trump-proud-boys-biden.html|archive-date=9 December 2020|archive-url=https://web.archive.org/web/20201209052024/https://www.nytimes.com/2020/09/29/us/trump-proud-boys-biden.html|url-status=live}} and the Myanmar junta using the app to communicate, both privately between members and publicly through channel posts. While Telegram made substantial efforts{{cite web |title=Telegram says it has had to remove 'hundreds' of public calls for violence |url=https://www.independent.co.uk/tech/telegram-capitol-riots-violence-messaging-apps-b1789603.html |website=The Independent |access-date=19 April 2024 |language=en |date=19 January 2021}}{{Cite web |url=https://www.crikey.com.au/2020/10/19/telegram-bans-350000-child-abusers-terrorists/|last=Ravlic |first=Tom |title=This dark world: messaging app bans more than 350,000 child abusers and terrorists |publisher=Crikey|date=19 October 2020}} to ban illegal content such as child abuse and pro-terrorist channels, including a partnership with Europol{{cite web |title=Europol and Telegram take on terrorist propaganda online |url=https://www.europol.europa.eu/media-press/newsroom/news/europol-and-telegram-take-terrorist-propaganda-online |website=Europol |access-date=19 April 2024 |language=en}} to eliminate IS presence on the platform, communities of far-left and far-right extremist users are still found on the app. Such content is usually linked to Telegram allowing misinformation on the platform as, according to founder and CEO Pavel Durov, "conspiracy theories only strengthen each time their content is removed by moderators".{{cite web |title=Du Rove's Channel |url=https://t.me/durov/163 |website=Telegram |date=20 July 2021 |access-date=19 April 2024 |url-status=live |archive-url=https://web.archive.org/web/20240422115238/https://t.me/s/durov/163 |archive-date=22 April 2024 }}

In September 2024, Telegram announced that it will begin to hand over users' IP addresses and phone numbers to authorities who have search warrants or other valid legal requests.{{Cite web |date=23 September 2024 |title=Telegram will now provide some user data to authorities |url=https://www.bbc.co.uk/news/articles/cvglp0xny3eo |access-date=12 November 2024 |website=BBC News |language=en-GB}}

In September 2015, in response to a question about the use of Telegram by Islamic State (ISIS), Pavel Durov stated: "I think that privacy, ultimately, and our right for privacy is more important than our fear of bad things happening, like terrorism."{{cite web|title = Telegram Now Seeing 12BN Daily Messages, Up From 1BN In February|url = https://techcrunch.com/2015/09/21/telegram-now-seeing-12bn-daily-messages-up-from-1m-in-february/|website = TechCrunch|access-date = 19 November 2015|first = Natasha|last = Lomas| date=21 September 2015 |archive-date = 27 November 2015|archive-url = https://web.archive.org/web/20151127133011/http://techcrunch.com/2015/09/21/telegram-now-seeing-12bn-daily-messages-up-from-1m-in-february/|url-status = live}} Durov sarcastically suggested to ban words because terrorists use them for communication.{{cite web|url=https://www.vesti.ru/doc.html?id=2687387|title=Дуров о запрете на Telegram: предлагаю запретить слова, с помощью них общаются террористы|website=vesti.ru|language=ru|access-date=24 April 2018|archive-date=2 May 2019|archive-url=https://web.archive.org/web/20190502055024/https://www.vesti.ru/doc.html?id=2687387|url-status=live}}

ISIS has used Telegram for recruiting attempts with some cells recommending the app{{cite web |last1=Hamblen |first1=Matt |title=Paris attacks demand 'wake-up call' on smartphone encryption |url=https://www.csoonline.com/article/3005570/paris-attacks-demand-wake-up-call-on-smartphone-encryption.html |website=CSO Online |language=en}} to their followers. In France, initial investigations{{cite news|url=http://www.cnn.com/2016/08/01/europe/france-church-attack-telegram/index.html|title=Killers of French priest met 4 days before attack|first1=Margot|last1=Haddad|first2=Tim|last2=Hume|publisher=cnn.com|access-date=24 September 2016|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512224348/https://www.cnn.com/2016/08/01/europe/france-church-attack-telegram/index.html|url-status=live}} of a terrorist act revealed the perpetrators used Telegram to communicate, though follow-up research suggested that the extent of the app's use was "unclear".{{cite web |last1=Stone |first1=Jeff |title=ISIS Terrorists Used 'Burner' Phones: Report |url=https://www.ibtimes.com/isis-terrorists-used-disposable-burner-phones-activated-just-hours-carry-out-paris-2340265 |website=International Business Times |date=21 March 2016}} Beginning in December 2016, Telegram began publishing daily moderation statistics regarding terror-related content in an official channel named @ISISwatch.{{cite web |title=ISIS Watch |url=http://t.me/ISISwatch |website=Telegram}} Following efforts by Telegram to remove ISIS-related content from the platform,{{cite web|title=Indonesian government lifts ban on messaging service Telegram|url=http://www.straitstimes.com/asia/se-asia/indonesian-government-lifts-ban-on-messaging-service-telegram|website=The Straits Times|publisher=SPH Digital News|date=11 August 2017|access-date=30 December 2017|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512225245/https://www.straitstimes.com/asia/se-asia/indonesian-government-lifts-ban-on-messaging-service-telegram|url-status=live}} the terrorist organization reportedly moved its recruitment groups to the dark web,{{cite web|title = Encrypted messaging app Telegram shuts down Islamic State propaganda channels|url = https://www.telegraph.co.uk/technology/news/12004892/Encrypted-messaging-app-Telegram-shuts-down-Islamic-State-propaganda-channels.html|website = Telegraph.co.uk| date=19 November 2015 |access-date = 19 November 2015|archive-date = 12 May 2019|archive-url = https://web.archive.org/web/20190512224337/https://www.telegraph.co.uk/technology/news/12004892/Encrypted-messaging-app-Telegram-shuts-down-Islamic-State-propaganda-channels.html|url-status = live}} with US officials citing the app's purging of terrorist content as particularly effective{{cite web|url=https://www.voanews.com/a/europe_struggles-regain-social-media-footing-after-europe-crackdown/6180532.html|title=IS Struggles to Regain Social Media Footing After Europe Crackdown|website=Voice of America|date=4 December 2019 |language=en|access-date=5 December 2019|archive-date=8 August 2020|archive-url=https://web.archive.org/web/20200808102410/https://www.voanews.com/europe/struggles-regain-social-media-footing-after-europe-crackdown|url-status=live}} at deplatforming ISIS.

In 2023, Saudi Arabia's Global Center for Combating Extremist Ideology (Etidal) reported that in collaboration with Telegram, over 59 million pieces of extremist content had been removed from the platform since 2022.{{cite web |title=Saudi Arabia's Etidal, Telegram remove 59m items of extremist content since 2022 |url=https://www.arabnews.com/node/2445716/saudi-arabia |website=Arab News |language=en |date=21 January 2024}}

Throughout 2020, the Islamic Revolutionary Guard Corps used groups and channels to dox Iraqi and Iranian citizens, while sharing propagandistic posts on the platform.{{cite web |last1=Lawati |first1=Abbas Al |title=Cartoons and Quranic verses form the latest Saudi-Iran battleground |url=https://edition.cnn.com/2022/11/04/middleeast/iran-saudi-cartoons-quran-mime-intl/index.html |website=CNN |language=en |date=4 November 2022}}{{cite web | url=https://www.cjr.org/the_feature/iraqi-journalists-watch-telegram-telegram-is-watching-them-back.php | title=Iraqi journalists watch Telegram. Telegram is watching them back }} After the 2021 coup d'état in Myanmar, Telegram channels were used by the junta to spread propaganda{{Cite web |date=9 June 2022 |title=How Myanmar lobbyists use Telegram to spread propaganda, fake news |url=https://www.mizzima.com/article/how-myanmar-lobbyists-use-telegram-spread-propaganda-fake-news |access-date=21 March 2023 |website=Mizzima Myanmar News and Insight |language=en}} and organize misinformation campaigns against pro-democracy groups. In response to the Office of the United Nations High Commissioner for Human Rights call to prevent such abuse, Telegram reportedly banned 13 accounts related to or supporting the Myanmar military.{{Cite web |title=Myanmar: Social media companies must stand up to junta's online terror campaign say UN experts |url=https://www.ohchr.org/en/press-releases/2023/03/myanmar-social-media-companies-must-stand-juntas-online-terror-campaign-say |access-date=21 March 2023 |website=OHCHR |language=en}}

On 26 April 2023, Telegram was temporarily suspended throughout Brazil, and the company was fined {{BRLConvert|1|m|year=2023|force=yes}} per day for not complying with a Federal Police investigation into neo-Nazi activities on the platform. The company only partially fulfilled a court request for personal data on two anti-Semitic Telegram groups, which authorities considered an intentional lack of cooperation. The decision was made after a series of violent school attacks, with at least one incident being linked to exchanges on an anti-Semitic group.{{cite news |title=Brazil court suspends Telegram app in neo-Nazi probe |url=https://www.france24.com/en/live-news/20230426-brazil-court-suspends-telegram-app-in-neo-nazi-probe |access-date=27 April 2023 |work=France 24 |agency=Agen ce France-Presse |date=26 April 2023 |location=Rio de Janeiro}} The Telegram CEO then said that the requested data was technologically impossible to obtain.{{cite news |title=Telegram CEO claims complying with Brazil order impossible |url=https://www.washingtonpost.com/business/2023/04/27/telegram-brazil-block/2ec1c1de-e554-11ed-9696-8e874fd710b8_story.html |access-date=10 May 2023 |newspaper=The Washington Post |date=27 April 2023}} A federal court lifted the suspension three days later, but upheld the daily fine.{{cite news |title=Telegram app back on in Brazil after judge lifts suspension |url=https://thehill.com/homenews/ap/ap-technology/telegram-app-back-on-in-brazil-after-judge-lifts-suspension/ |access-date=30 April 2023 |work=The Hill |agency=Associated Press |date=29 April 2023}} Twelve days later, Telegram told its users that the Brazilian Congressional Bill No. 2630 against online disinformation, which was about to be approved, would end freedom of speech in the country.{{cite news |title=Telegram calls Brazil disinformation law 'attack on democracy' |url=https://www.france24.com/en/live-news/20230509-telegram-calls-brazil-disinformation-law-attack-on-democracy |access-date=10 May 2023 |work=France 24 |agency=Agence France-Presse |date=9 May 2023}}

Far-right and white supremacist communities on Telegram have spread videos of the Christchurch and Halle shootings{{cite web |date=2 December 2019 |title=Telegram: The Latest Safe Haven for White Supremacists |url=https://www.adl.org/blog/telegram-the-latest-safe-haven-for-white-supremacists |url-status=live |archive-url=https://web.archive.org/web/20201117191415/https://www.adl.org/blog/telegram-the-latest-safe-haven-for-white-supremacists |archive-date=17 November 2020 |access-date=11 March 2020 |website=Anti-Defamation League}} in groups and channels after the original livestreams were taken down by Twitch. British far-right publication TR.news,{{cite journal |last1=Rogers |first1=Richard |title=Deplatforming: Following extreme Internet celebrities to Telegram and alternative social media |journal=European Journal of Communication |date=June 2020 |volume=35 |issue=3 |pages=213–229 |doi=10.1177/0267323120922066 }} following multiple deplatformings, launched a Telegram channel to spread its posts and the Institute for Strategic Dialogue{{cite web|last=Lanigan|first=Michael|url=https://www.vice.com/en/article/telegram-is-the-far-rights-weapon-of-choice-in-ireland/|title=Telegram Is the Far-Right's Weapon of Choice in Ireland|date=30 April 2021|website=Vice|access-date=2 May 2021|archive-date=2 May 2021|archive-url=https://web.archive.org/web/20210502124822/https://www.vice.com/en/article/93yw4p/telegram-is-the-far-rights-weapon-of-choice-in-ireland|url-status=live}} reported that Irish far-right groups grew substantially between 2019 and 2020. However, research from the Oxford University{{cite web|website=The Computational Propaganda Project|title=Junk News Distribution on Telegram: The Visibility of English-language News Sources on Public Telegram Channels|date=20 July 2020|access-date=1 November 2020|url=https://comprop.oii.ox.ac.uk/research/posts/junk-news-distribution-on-telegram-the-visibility-of-english-language-news-sources-on-public-telegram-channels/|archive-date=3 December 2020|archive-url=https://web.archive.org/web/20201203103647/https://comprop.oii.ox.ac.uk/research/posts/junk-news-distribution-on-telegram-the-visibility-of-english-language-news-sources-on-public-telegram-channels/|url-status=live}} suggests that, due to Telegram not using sorting algorithms in its search function, many such groups remain obscure and small while select others receive a lot of attention.

Telegram has been used to distribute illegal pornography, including child pornography.{{cite web|url=https://mashable.com/article/nudes-revenge-porn-crime-telegram/|title=Telegram's massive revenge porn problem has made these women's lives hell|date=29 October 2020|website=Mashable|access-date=28 January 2021|archive-date=28 January 2021|archive-url=https://web.archive.org/web/20210128165434/https://mashable.com/article/nudes-revenge-porn-crime-telegram/|url-status=live}}{{cite web|url=https://theprint.in/tech/rape-videos-child-porn-terror-telegram-anonymity-is-giving-criminals-a-free-run/307959/|title=Rape videos, child porn, terror — Telegram anonymity is giving criminals a free run|date=19 October 2019|website=The Print|access-date=28 January 2021|archive-date=8 February 2021|archive-url=https://web.archive.org/web/20210208201355/https://theprint.in/tech/rape-videos-child-porn-terror-telegram-anonymity-is-giving-criminals-a-free-run/307959/|url-status=live}} Telegram's internal reporting system has an option to report content that contains child abuse, including specific messages in groups and channels. The company has a verified channel called "Stop Child Abuse", where daily statistics on the number of groups and channels banned for sharing illegal materials are posted. It also provides an email address dedicated to reports of content related to child abuse.{{cite web |url=https://t.me/s/stopCA |title=Stop Child Abuse – Telegram |website=Telegram |access-date=24 September 2021 |url-status=live |archive-date=15 November 2021 |archive-url=https://web.archive.org/web/20211115225608/https://t.me/s/stopCA }}{{cite web |url=https://edition.cnn.com/2021/01/15/asia/south-korea-telegram-digital-sex-intl-hnk-dst/index.html |title=South Korea is cracking down on digital sex crimes. Has it done enough? |date=17 January 2021 |website=CNN |access-date=24 September 2021 |url-status=live |archive-date=24 September 2021 |archive-url=https://web.archive.org/web/20210924162734/https://edition.cnn.com/2021/01/15/asia/south-korea-telegram-digital-sex-intl-hnk-dst/index.html }}

In January 2021, North Macedonian media outlets reported that a now-banned Telegram group, with more than 7,000 members, titled "Public Room" ("Јавна соба") was used to share nude photos of women, often young teenage girls.{{cite web|url=https://english.republika.mk/news/macedonia/users-of-telegram-group-where-pictures-of-underage-girls-were-shared-are-threatening-the-woman-who-reported-them/|title=Users of Telegram group where pictures of underage girls were shared are threatening the woman who reported them|date=27 January 2021|website=Republika English|access-date=28 January 2021|archive-date=27 January 2021|archive-url=https://web.archive.org/web/20210127095816/https://english.republika.mk/news/macedonia/users-of-telegram-group-where-pictures-of-underage-girls-were-shared-are-threatening-the-woman-who-reported-them/|url-status=live}} Along with the shared photographs, anonymous accounts shared private information of the women, including phone numbers and social media profiles, encouraging members of the group to contact the women and ask for sexual favors.{{cite web|url=https://english.republika.mk/news/macedonia/one-of-the-girls-whose-pictures-were-shared-in-a-telegram-group-demands-action/|title=One of the girls whose pictures were shared in a Telegram group demands action|date=27 January 2021|website=Republika English|access-date=28 January 2021|archive-date=27 January 2021|archive-url=https://web.archive.org/web/20210127134346/https://english.republika.mk/news/macedonia/one-of-the-girls-whose-pictures-were-shared-in-a-telegram-group-demands-action/|url-status=live}}

This was done without prior agreement or knowledge of the women, causing intense public backlash and demand for the group to be shut down. The President of North Macedonia Stevo Pendarovski, along with the Prime Minister of North Macedonia Zoran Zaev, demanded an immediate reaction from Telegram and threatened to completely restrict access to the app in the country if no actions were taken.{{cite web|url=https://english.republika.mk/news/macedonia/calls-to-shut-down-telegram-group-used-to-share-pictures-of-underage-girls/|title=Calls to shut down Telegram group used to share pictures of underage girls|date=28 January 2021|website=Republika English|access-date=28 January 2021|archive-date=28 January 2021|archive-url=https://web.archive.org/web/20210128111846/https://english.republika.mk/news/macedonia/calls-to-shut-down-telegram-group-used-to-share-pictures-of-underage-girls/|url-status=live}}{{Cite web |url=https://twitter.com/Zoran_Zaev/status/1354759939902894081 |title=Зоран Заев on Twitter |access-date=28 January 2021 |archive-date=28 January 2021 |archive-url=https://web.archive.org/web/20210128115555/https://twitter.com/Zoran_Zaev/status/1354759939902894081 |url-status=live }} The group was banned after reports from users and media, although no public statement was made.

An investigation published in August 2024 by the BBC showed that Telegram has not responded to requests to join the US–based National Center for Missing & Exploited Children (NCMEC), nor from the UK–based Internet Watch Foundation, both non–profit NGOs. Telegram responded to the BBC's reporting, stating that Telegram "proactively moderates harmful content on its platform including child abuse material", and that its moderation is "within industry standards and constantly improving".{{cite news|url=https://www.bbc.com/news/articles/cy54905nv0go|title=Telegram repeatedly refuses to join child protection schemes|website=BBC News|access-date=28 August 2024}}

In August 2024, journalist Ko Narin of the Hankyoreh exposed Telegram chats of teenagers who used generative AI to deepfake images of their classmates and teachers for porn.{{cite web|url=https://www.bbc.com/news/articles/cpdlpj9zn9go|title=Inside the deep fake porn crisis engulfing Korean schools|date=3 September 2024 |publisher=BBC News}}{{cite web|url=https://www.npr.org/2024/09/06/nx-s1-5101891/south-korea-deepfake|title=South Korea investigates Telegram over alleged sexual deepfakes|work=NPR |date=6 September 2024 |last1=Gong |first1=Se Eun }}

Volodymyr Flents, the chairman of the public organization "Electronic Democracy", announced on 11 May 2020 that a Telegram bot appeared on the Web, which sold the personal data of Ukrainian citizens. It is estimated that the bot contains data from 26 million Ukrainians registered in the Diia application. However, deputy prime minister and minister of digital transformation Mykhailo Fedorov denied any data from the app being leaked. The criminal activity of 25 people was confirmed and copies of 30 databases were seized.{{Cite web|title=Утечка данных из анонимного Тelegram-канала: объявили 25 подозрений|url=https://www.ukrinform.ru/rubric-society/3051656-utecka-dannyh-iz-anonimnogo-telegramkanala-obavili-25-podozrenij.html|website=www.ukrinform.ru|access-date=25 June 2020|archive-date=11 November 2020|archive-url=https://web.archive.org/web/20201111073614/https://www.ukrinform.ru/rubric-society/3051656-utecka-dannyh-iz-anonimnogo-telegramkanala-obavili-25-podozrenij.html|url-status=usurped}}{{Cite web|date=19 June 2020|title=Cyber police searched for leaks in public and private databases | Techumble|url=https://techumble.com/cyber-%e2%80%8b%e2%80%8bpolice-searched-for-leaks-in-public-and-private-databases/|archive-url=https://web.archive.org/web/20200628012411/https://techumble.com/cyber-%E2%80%8B%E2%80%8Bpolice-searched-for-leaks-in-public-and-private-databases/|url-status=dead|archive-date=28 June 2020|website=techumble.com|access-date=13 May 2021}}{{Cite web|date=12 May 2020|title=Ukrainian data leak via telegram: MP will send requests to SBU and police | Techumble|url=https://techumble.com/ukrainian-data-leak-via-telegram-mp-will-send-requests-to-sbu-and-police/|website=techumble.com|access-date=25 June 2020|archive-date=25 October 2020|archive-url=https://web.archive.org/web/20201025142849/https://techumble.com/ukrainian-data-leak-via-telegram-mp-will-send-requests-to-sbu-and-police/|url-status=live}}

In 2020, a Telegram bot was blocked by Apple after posting deepfake pornography.{{Cite news|title=The AI Telegram bot that abused women is still out of control|language=en-GB|magazine=Wired UK|url=https://www.wired.co.uk/article/porn-bots-in-telegram-deepfake|access-date=27 June 2021|issn=1357-0978|archive-date=27 January 2021|archive-url=https://web.archive.org/web/20210127065028/https://www.wired.co.uk/article/porn-bots-in-telegram-deepfake|url-status=live}} In the same year, Telegram reportedly banned more than 350,000 bots and channels, including those that contained child abuse and terrorism-related content.

In 2021, a bot was found selling leaked phone numbers from Facebook.{{Cite web|title=Facebook users' phone numbers are for sale through a Telegram bot|url=https://www.theverge.com/2021/1/25/22249571/facebook-phone-number-hack-telegram-bot|access-date=26 January 2021|website=www.theverge.com|date=25 January 2021|language=en|archive-date=26 January 2021|archive-url=https://web.archive.org/web/20210126113721/https://www.theverge.com/2021/1/25/22249571/facebook-phone-number-hack-telegram-bot|url-status=live}}

Telegram has received criticism for its failure to curb fraud on the platform. The most common mode of fraud involves scammers sending messages to unsuspecting users, offering part-time online jobs which comprise a series of tasks. Scammers employ a variety of confidence tricks to entice users into completing "prepaid tasks" in which users deposit money into scammers' accounts with the expectation of receiving high returns.{{cite news |title=Several job-seekers cheated in Telegram scam, Tambaram police urge cellphone users to be vigilant |url=https://www.thehindu.com/news/cities/chennai/several-job-seekers-in-telegram-scam-tambaram-urge-cellphone-users-to-be-vigilant/article66900587.ece |access-date=30 October 2023 |work=The Hindu |date=28 May 2023 |language=en-IN}}{{cite news |title=Don't take the bait dropped through that missed call |url=https://www.onmanorama.com/news/india/2023/05/25/online-fraid-missed-call-telegram-whatsapp.html |access-date=30 October 2023 |work=OnManorama}}

In July 2023, Hyderabad Police uncovered a fraud wherein 15,000 Indian citizens were duped out of {{INRconvert|712|c}} in less than a year, all related to "prepaid tasks" on Telegram. A cybercrime police investigation of the money trail revealed that the fraud originated from China and the money was laundered by mules through cryptocurrency wallets.{{cite news |title=Fraudsters dupe 15,000 people of ₹712 crore, launders money to China |url=https://www.livemint.com/news/india/fraudsters-dupe-15-000-people-of-rs-712-crore-launders-money-to-china-this-is-how-they-operated-11690206228894.html |access-date=30 October 2023 |work=mint |date=24 July 2023 |language=en}}{{cite news |title=No platform is fool proof, says Telegram on Rs 712 crore investment fraud |url=https://www.moneycontrol.com/news/business/no-platform-is-fool-proof-says-telegram-on-rs-712-crore-investment-fraud-11063831.html |access-date=30 October 2023 |work=Moneycontrol |date=31 July 2023 |language=en}}

In September 2023, the Singapore Police Force stated that more than 6,600 Singaporeans had lost over {{SGDConvert|96.8|m}} to prepaid job scams on Telegram and WhatsApp since the start of the year.{{cite news |last1=Sin |first1=Carmen |title=Police warn of online job scam; 6,600 victims have lost $96.8m since January |url=https://www.straitstimes.com/singapore/police-warn-of-fake-online-job-scam-6600-victims-lost-968m-since-january |access-date=12 November 2023 |work=The Straits Times |date=16 September 2023 |language=en}}

In March 2024, a judge of Spain's Audiencia Nacional ordered the temporary blocking of Telegram in Spain. The order came following a complaint from media organizations —Mediaset, Atresmedia and Movistar Plus+— saying that the app allowed users to share copyrighted content without their consent.{{cite news|title=Spain's High Court orders block on Telegram messaging app as a precautionary measure|url=https://www.euronews.com/next/2024/03/23/spains-high-court-orders-block-on-telegram-messaging-app-as-a-precautionary-measure |work=Euronews |date=23 March 2024 |language=en}}{{cite news|title=High Court orders temporary suspension of Telegram's services in Spain|url=https://www.reuters.com/world/europe/high-court-orders-temporary-suspension-telegrams-services-spain-2024-03-23/ |work=Reuters |date=23 March 2024 |language=en}} A few days later, following repeated criticism, the same judge suspended his order until the police issue a report on the consequences that this measure would have for users.{{Cite news |last1=Marraco |first1=Manuel |last2=Diego Madueño |first2=Juan |date=25 March 2024 |title=Pedraz suspende el bloqueo de Telegram hasta recibir un informe sobre la incidencia en los usuarios |url=https://www.elmundo.es/papel/2024/03/25/66014c77e9cf4a84758b4570.html |access-date=25 March 2024 |work=El Mundo |language=es}} Finally, the judge annulled the order, considering it "disproportionate".{{Cite web |date=25 March 2024 |title=Pedraz suspende el bloqueo de Telegram por considerarlo "excesivo y desproporcionado" |url=https://www.elmundo.es/papel/2024/03/25/66014c77e9cf4a84758b4570.html |access-date=25 March 2024 |website=ELMUNDO |language=es}}

In recent years, Telegram has become more popular for the purpose of buying and selling illicit drugs. In 2024, Sociology Compass released a paper exploring this trend in drug trade.{{Cite journal |last1=Dewey |first1=Matías |last2=Buzzetti |first2=Andrés |date=February 2024 |title=Easier, faster and safer: The social organization of drug dealing through encrypted messaging apps |journal=Sociology Compass |language=en |volume=18 |issue=2 |doi=10.1111/soc4.13175 |issn=1751-9020|doi-access=free }}

In August 2024, an EU probe was launched into Telegram to determine whether the platform breached EU digital rules by failing to provide accurate user numbers.{{Cite news |last1=Klasa |first1=Adrienne |last2=Foy |first2=Henry |last3=Hancock |first3=Alice |last4=Tamma |first4=Paola |date=28 August 2024 |title=EU investigating Telegram over user numbers |url=https://www.ft.com/content/1f96e66d-00fe-46ca-9cb8-73e526125922 |access-date=12 November 2024 |work=Financial Times}} Telegram said in February 2024 that it had 41mn users in the EU. Under the EU's Digital Services Act (DSA), Telegram was supposed to provide an updated number in August but failed to do so, only declaring it had "significantly fewer than 45mn average monthly active recipients in the EU".{{Cite news |last1=Klasa |first1=Adrienne |last2=Foy |first2=Henry |last3=Hancock |first3=Alice |last4=Tamma |first4=Paola |date=28 August 2024 |title=EU investigating Telegram over user numbers |url=https://www.ft.com/content/1f96e66d-00fe-46ca-9cb8-73e526125922 |access-date=12 November 2024 |work=Financial Times}}

Channels have been used by celebrities such as Arnold Schwarzenegger{{cite web |last1=Schwarzenegger |first1=Arnold |title=You can and anyone you know also find this on my new Telegram channel if that is easier |url=https://twitter.com/Schwarzenegger/status/1504429787481194499 |website=Twitter }} and Snoop Dogg{{Cite web |title=Snoop Dogg |url=https://t.me/snoopdogg |access-date=2025-06-15 |website=Telegram}} and politicians: President of France Emmanuel Macron,{{Cite web |title=Emmanuel Macron |url=https://t.me/emmanuelmacron |access-date=1 July 2022 |website=Telegram}} former President of Brazil Jair Bolsonaro,{{Cite web |title=Jair M. Bolsonaro 1 |url=https://t.me/jairbolsonarobrasil |access-date=1 July 2022 |website=Telegram}} Turkish President Recep Tayyip Erdoğan,{{Cite web |title=Recep Tayyip Erdoğan |url=https://t.me/RTErdogan |access-date=1 July 2022 |website=Telegram}} President of Moldova Maia Sandu,{{Cite web |title=🇲🇩 Președintele Maia Sandu |url=https://t.me/maiasandumd/16 |access-date=10 June 2022 |website=Telegram}} President of Ukraine Volodymyr Zelenskyy, former Mexican President Andrés Manuel López Obrador,{{Cite web |title=Andrés Manuel López Obrador |url=https://t.me/PresidenteAMLO |access-date=1 July 2022 |website=Telegram}} former Singaporean Prime Minister Lee Hsien Loong,{{Cite web |title=Lee Hsien Loong |url=https://t.me/leehsienloong |access-date=1 July 2022 |website=Telegram}} President of Uzbekistan Shavkat Mirziyoyev,{{Cite web |title=Shavkat Mirziyoyev_press-service |url=https://t.me/shmirziyoyev |access-date=2025-06-15 |website=Telegram}} former Taiwan President Tsai Ing-wen, Ethiopian Prime Minister Abiy Ahmed,{{Cite web |title=Abiy Ahmed Ali 🇪🇹 |url=https://t.me/AbiyAhmedAliofficial |access-date=2025-06-15 |website=Telegram}} Israeli Prime Minister Benjamin Netanyahu{{Cite web |title=בנימין נתניהו |url=https://t.me/bnetanyahu |access-date=2025-06-15 |website=Telegram}} and others.

Telegram's security model has received notable criticism by cryptography experts. They criticized how, unless modified first, the default general security model stores all contacts, messages and media together with their decryption keys on its servers continuously; and that it does not enable end-to-end encryption for messages by default.{{cite web|last1=Turton|first1=William|title=Why You Should Stop Using Telegram Right Now|url=https://gizmodo.com/why-you-should-stop-using-telegram-right-now-1782557415|website=Gizmodo|publisher=Gawker Media|access-date=22 December 2020|date=24 June 2016|archive-date=8 July 2016|archive-url=https://web.archive.org/web/20160708145705/http://gizmodo.com/why-you-should-stop-using-telegram-right-now-1782557415|url-status=live}} Pavel Durov has argued that this is because it helps to avoid third-party unsecured backups, and to allow users to access messages and files from any device. Criticisms were also aimed at Telegram's use of a custom-designed encryption protocol.{{harvnb|Jakobsen|Orlandi|2015}}{{cite web|last1=Cox|first1=Joseph|title=Why You Don't Roll Your Own Crypto|url=https://www.vice.com/en/article/why-you-dont-roll-your-own-crypto/|website=Motherboard|publisher=Vice Media|access-date=22 December 2020|date=10 December 2015|archive-date=26 December 2016|archive-url=https://web.archive.org/web/20161226174309/http://motherboard.vice.com/read/why-you-dont-roll-your-own-crypto|url-status=live}}{{cite news|last1=Turton|first1=William|title=Cryptography expert casts doubt on encryption in ISIS' favorite messaging app|url=http://www.dailydot.com/politics/telegram-isis-encryption-cryptography/|website=The Daily Dot|access-date=11 December 2015|date=19 November 2015|archive-date=27 June 2016|archive-url=https://web.archive.org/web/20160627184947/http://www.dailydot.com/politics/telegram-isis-encryption-cryptography/|url-status=live}}

In December 2020, a study titled "Automated Symbolic Verification of Telegram's MTProto 2.0" was published, confirming the security of the updated MTProto 2.0 and reviewing it while pointing out several theoretical vulnerabilities.{{harvnb|Miculan|Vitacolonna|2020}}{{harvnb|Miculan|Vitacolonna|2023}} The paper provides "fully automated proof of the soundness of MTProto 2.0's authentication, normal chat, end-to-end encrypted chat, and re-keying mechanisms with respect to several security properties, including authentication, integrity, confidentiality and perfect forward secrecy" and "proves the formal correctness of MTProto 2.0". This partially addresses the concern about the lack of scrutiny while confirming the formal security of the protocol's latest version.

The desktop clients, excluding the macOS client, do not feature options for end-to-end encrypted messages. When the user assigns a local password in the desktop application, data is also locally encrypted. Telegram has defended the lack of ubiquitous end-to-end encryption by saying that online-backups that do not use client-side encryption are "the most secure solution currently possible".{{cite web|url=https://telegram.org/faq#q-why-not-just-make-all-chats-secret|title=Telegram F.A.Q.|website=Telegram|access-date=1 October 2017|archive-date=9 February 2014|archive-url=https://web.archive.org/web/20140209082001/https://telegram.org/faq#q-why-not-just-make-all-chats-secret|url-status=live}}

In May 2016, critics disputed claims by Telegram that it is "more secure than mass market messengers like WhatsApp and Line", as WhatsApp claims to apply end-to-end encryption to all of its traffic by default and uses the Signal Protocol, which has been "reviewed and endorsed by leading security experts", while Telegram does neither and stores all messages, media and contacts in their cloud. Since July 2016, Line has also applied end-to-end encryption to all of its messages by default,{{cite web|last1=Sawers|first1=Paul|title=Ahead of IPO, mobile messaging giant Line introduces end-to-end encryption by default|url=https://venturebeat.com/2016/06/30/ahead-of-ipo-mobile-messaging-giant-line-introduces-end-to-end-encryption-by-default/|website=VentureBeat|access-date=22 December 2020|date=30 June 2016|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512184542/https://venturebeat.com/2016/06/30/ahead-of-ipo-mobile-messaging-giant-line-introduces-end-to-end-encryption-by-default/|url-status=live}} though it has also been criticized for being susceptible to replay attacks and the lack of forward secrecy between clients.{{harvnb|Espinoza|Tolley|Crandall|2017}}

In 2013, an author on the Russian programming website Habr discovered a weakness in the first version of MTProto that would allow an attacker to mount a man-in-the-middle attack and prevent the victim from being alerted by a changed key fingerprint. The bug was fixed on the day of the publication with a $100,000 payout to the author and a statement on Telegram's official blog.{{Cite web|title=Crowdsourcing a More Secure Future|url=https://telegram.org/blog/crowdsourcing-a-more-secure-future|date=21 December 2013|access-date=12 May 2021|website=Telegram|language=en|archive-date=26 December 2018|archive-url=https://web.archive.org/web/20181226140722/https://telegram.org/blog/crowdsourcing-a-more-secure-future%20|url-status=live}}

On 26 February 2014, the German consumer organization Stiftung Warentest evaluated several data-protection aspects of Telegram, along with other popular instant-messaging clients. Among the aspects considered were: the security of the data transmission, the service's terms of use, the accessibility of the source code, and the distribution of the app. Telegram was rated 'problematic' ({{Lang|de|kritisch}}) overall. The organization was favorable to Telegram's secure chats and partially free code but criticized the mandatory transfer of contact data to Telegram's servers and the lack of an imprint or address on the service's website. It noted that while the message data is encrypted on the device, it could not analyze the transmission due to a lack of source code.{{cite web|url=https://www.test.de/WhatsApp-und-Alternativen-Datenschutz-im-Test-4675013-0/|title=WhatsApp und Alternativen: Datenschutz im Test|date=26 February 2014|website=Stiftung Warentest|language=de|trans-title=WhatsApp and alternatives: data protection tested|access-date=22 December 2020|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512185648/https://www.test.de/WhatsApp-und-Alternativen-Datenschutz-im-Test-4675013-0/|url-status=live}}

The Electronic Frontier Foundation (EFF) listed Telegram on its "Secure Messaging Scorecard" in February 2015. Telegram's default chat function received a score of 4 out of 7 points on the scorecard. It received points for having communications encrypted in transit, having its code open to independent review, having the security design properly documented, and having completed a recent independent security audit. Telegram's default chat function missed points because the communications were not encrypted with keys the provider did not have access to, users could not verify contacts' identities, and past messages were not secure if the encryption keys were stolen. Telegram's optional secret chat function, which provides end-to-end encryption, received a score of 7 out of 7 points on the scorecard.{{cite web |url=https://www.eff.org/node/82654 |title=Secure Messaging Scorecard |date=17 February 2015 |website=Electronic Frontier Foundation |access-date=20 July 2016 |archive-date=28 July 2016 |archive-url=https://web.archive.org/web/20160728011841/https://www.eff.org/node/82654 |url-status=live }} The EFF said that the results "should not be read as endorsements of individual tools or guarantees of their security", and that they were merely indications that the projects were "on the right track".

In December 2015, two researchers from Aarhus University published a report in which they demonstrated that MTProto 1.0 did not achieve indistinguishability under chosen-ciphertext attack (IND-CCA) or authenticated encryption.{{harvnb|Jakobsen|Orlandi|2015|p=6}} The researchers stressed that the attack was of a theoretical nature and they "did not see any way of turning the attack into a full plaintext-recovery attack". Nevertheless, they said they saw "no reason why [Telegram] should use a less secure encryption scheme when more secure (and at least as efficient) solutions exist".{{harvnb|Jakobsen|Orlandi|2015|p=1}} The Telegram team responded that the flaw does not affect message security{{cite web|title=FAQ for the Technically Inclined: What about IND-CCA?|url=https://core.telegram.org/techfaq#what-about-ind-cca|website=Telegram|access-date=25 March 2017|archive-date=28 January 2017|archive-url=https://web.archive.org/web/20170128144833/https://core.telegram.org/techfaq#what-about-ind-cca|url-status=live}} and that "a future patch would address the concern".{{cite web|last1=Clary|first1=Grayson|title=The Flaw in ISIS's Favorite Messaging App|url=https://www.theatlantic.com/technology/archive/2016/01/isiss-favorite-messaging-app-has-a-security-problem/422460/|website=The Atlantic|date=4 January 2016|access-date=25 March 2017|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512210359/https://www.theatlantic.com/technology/archive/2016/01/isiss-favorite-messaging-app-has-a-security-problem/422460/|url-status=live}} Telegram 4.6, released in December 2017, supports MTProto 2.0, which now satisfied the conditions for IND-CCA.{{cite web|title=FAQ for the Technically Inclined|url=https://core.telegram.org/techfaq#what-about-ind-cca|website=Telegram|access-date=9 December 2017|archive-date=28 January 2017|archive-url=https://web.archive.org/web/20170128144833/https://core.telegram.org/techfaq#what-about-ind-cca|url-status=live}} MTProto 2.0 is seen by qualified cryptographers as a vast improvement to Telegram's security.

In April 2016, the accounts of several Russian opposition members were hijacked by intercepting the SMS messages used for login authorization. In response, Telegram recommended using the optional two-factor authentication feature. In May 2016, the Committee to Protect Journalists and Nate Cardozo, senior staff attorney at Electronic Frontier Foundation, recommended against using Telegram because of "its lack of end-to-end encryption [by default] and its use of non-standard MTProto encryption protocol, which has been publicly criticized by cryptography researchers, including Matthew Green".{{cite web|title=Why Telegram's security flaws may put Iran's journalists at risk|url=https://cpj.org/blog/2016/05/why-telegrams-security-flaws-may-put-irans-journal.php|publisher=Committee to Protect Journalists|access-date=20 July 2016|date=31 May 2016|archive-date=19 August 2016|archive-url=https://web.archive.org/web/20160819013449/https://cpj.org/blog/2016/05/why-telegrams-security-flaws-may-put-irans-journal.php|url-status=live}}

On 2 August 2016, Reuters reported that Iranian hackers compromised more than a dozen Telegram accounts and identified the phone numbers of 15 million Iranian users, as well as the associated user IDs. Researchers said the hackers belonged to a group known as Rocket Kitten. Rocket Kitten's attacks were similar to ones attributed to Iran's Islamic Revolutionary Guards Corps. The attackers took advantage of a programming interface built into Telegram. According to Telegram, these mass checks are no longer possible because of limitations introduced into its API earlier in 2016.{{Cite web|url=https://telegram.org/blog/15million-reuters|title=Keep Calm and Send Telegrams!|date=3 August 2016|website=Telegram|access-date=17 August 2020|archive-date=8 November 2020|archive-url=https://web.archive.org/web/20201108161904/https://telegram.org/blog/15million-reuters|url-status=live}}

Login SMS messages are known to have been intercepted in Iran, Russia and Germany, possibly in coordination with phone or telecom companies.{{cite web|last1=Lipp|first1=Sebastian|last2=Hoppenstedt|first2=Max|title=Exklusiv: Wie das BKA Telegram-Accounts von Terrorverdächtigen knackt|url=https://www.vice.com/de/article/exklusiv-wie-das-bka-telegram-accounts-von-terrorverdaechtigen-knackt/|website=Motherboard|publisher=Vice Media Inc.|access-date=5 December 2022|language=de|date=26 August 2016|archive-date=11 December 2016|archive-url=https://web.archive.org/web/20161211132159/http://motherboard.vice.com/de/read/exklusiv-wie-das-bka-telegram-accounts-von-terrorverdaechtigen-knackt|url-status=live}} Pavel Durov has said that Telegram users in "troubled countries" should enable two-factor authentication by creating passwords in order to prevent this.{{cite web|last1=Lokot|first1=Tetyana|title=Is Telegram Really Safe for Activists Under Threat? These Two Russians Aren't So Sure.|url=https://advox.globalvoices.org/2016/05/02/is-telegram-really-safe-for-activists-under-threat-these-two-russians-arent-so-sure/|website=Advox|publisher=Global Voices|access-date=4 May 2016|date=2 May 2016|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512143414/https://advox.globalvoices.org/2016/05/02/is-telegram-really-safe-for-activists-under-threat-these-two-russians-arent-so-sure/|url-status=live}}{{cite news|last1=Menn|first1=Joseph|last2=Torbati|first2=Yeganeh|title=Exclusive: Hackers accessed Telegram messaging accounts in Iran – researchers|url=https://www.reuters.com/article/us-iran-cyber-telegram-exclusive-idUSKCN10D1AM|access-date=3 August 2016|work=Reuters|publisher=Thomson Reuters|date=2 August 2016|location=San Francisco/Washington|archive-date=18 May 2019|archive-url=https://web.archive.org/web/20190518221135/https://www.reuters.com/article/us-iran-cyber-telegram-exclusive-idUSKCN10D1AM|url-status=live}}

In June 2017, Pavel Durov in an interview said that U.S. intelligence agencies tried to bribe the company's developers to weaken Telegram's encryption or install a backdoor during their visit to the U.S. in 2016.{{cite news|title=Telegram founder: U.S. intelligence agencies tried to bribe us to weaken encryption|url=https://news.fastcompany.com/telegram-founder-us-intelligence-agencies-tried-to-bribe-us-to-weaken-encryption-4040876|access-date=15 June 2017|work=FastCo News|date=15 June 2017|archive-date=19 July 2017|archive-url=https://web.archive.org/web/20170719075854/https://news.fastcompany.com/telegram-founder-us-intelligence-agencies-tried-to-bribe-us-to-weaken-encryption-4040876|url-status=live}}{{cite web|last1=Leyden|first1=John|title=Telegram chat app founder claims Feds offered backdoor bribe|url=https://www.theregister.co.uk/2017/06/14/telegram_boss_backdoor_offer_claim/|website=The Register|publisher=Situation Publishing|access-date=15 June 2017|date=14 June 2017|archive-date=12 May 2019|archive-url=https://web.archive.org/web/20190512211640/https://www.theregister.co.uk/2017/06/14/telegram_boss_backdoor_offer_claim/|url-status=live}}

In 2018, Telegram sent a message to all Iranian users stating that the Telegram Talai and Hotgram unofficial clients are not secure.{{Citation|title=هشدار تلگرام درباره ناامن بودن "هاتگرام" و "طلاگرام"|date=17 December 2018 |url=https://www.radiofarda.com/a/iran-messaging-apps-security-concerns/29661203.html|language=fa|access-date=18 January 2019|archive-date=20 November 2020|archive-url=https://web.archive.org/web/20201120071559/https://www.radiofarda.com/a/iran-messaging-apps-security-concerns/29661203.html|url-status=live}}

In March 2014, Telegram promised that "all code will be released eventually", including all the various client applications (Android, iOS, desktop, etc.) and the server-side code.{{cite web |title=Telegram F.A.Q. |url=https://telegram.org/faq#q-why-not-open-source-everything |archive-url=https://web.archive.org/web/20140309205427/https://telegram.org/faq#q-why-not-open-source-everything |archive-date=9 March 2014 |access-date=21 January 2019 |date=9 March 2014}} As of May 2021, Telegram had not published their server-side source code.{{cite web |title=Telegram F.A.Q. |url=https://telegram.org/faq#q-why-not-open-source-everything |archive-url=https://web.archive.org/web/20190114013309/https://telegram.org/faq#q-why-not-open-source-everything |archive-date=14 January 2019 |access-date=21 January 2019 |date=14 January 2019}} In January 2021, Durov explained his rationale for not releasing server-side code, citing reasons such as inability for end-users to verify that the released code is the same code run on servers, and a government that wanted to acquire the server code and make an instant messaging network that would end competitors.{{Cite web|url=https://t.me/durovschat/515221|title=Durov's Chat|website=Telegram|access-date=12 January 2021|archive-date=12 January 2021|archive-url=https://web.archive.org/web/20210112075204/https://t.me/durovschat/515221|url-status=live}}

On 9 June 2019, The Intercept released leaked Telegram messages exchanged between current Brazilian Minister of Justice and former judge Sérgio Moro and federal prosecutors.{{cite web |url=https://theintercept.com/series/secret-brazil-archive/ |title=Secret Brazil Archive — An Investigative Series by The Intercept |website=The Intercept |language=en |access-date=10 June 2019 |archive-date=28 November 2020 |archive-url=https://web.archive.org/web/20201128005348/https://theintercept.com/series/secret-brazil-archive/ |url-status=live }} The hypothesis is that either mobile devices were hacked by SIM swap or the targets' computers were compromised.{{cite web |url=https://noticias.uol.com.br/tecnologia/noticias/redacao/2019/06/10/como-hackers-tiveram-acesso-a-conversas-privadas-de-sergio-moro.htm |title=Como hackers tiveram acesso a conversas privadas de Sergio Moro? |website=noticias.uol.com.br |language=pt-br |access-date=10 June 2019 |archive-date=3 July 2019 |archive-url=https://web.archive.org/web/20190703162727/https://noticias.uol.com.br/tecnologia/noticias/redacao/2019/06/10/como-hackers-tiveram-acesso-a-conversas-privadas-de-sergio-moro.htm |url-status=live }} The Telegram team tweeted that it was either because the user had malware or they were not using two-step verification.{{Cite tweet |number=1138430205343731712 |user=telegram |title=Indeed, there's no evidence of any hack. Most likely to have been either malware or someone not using a 2-step verification password. |date=11 June 2019}}

On 12 June 2019, Telegram confirmed that it suffered a denial-of-service attack which disrupted normal app functionality for approximately one hour. Pavel Durov tweeted that the IP addresses used in the attack mostly came from China.{{Cite news|url=https://www.bbc.com/news/business-48619804|title=Telegram founder links cyber attack to China|date=13 June 2019|access-date=13 June 2019|language=en-GB|archive-date=11 July 2019|archive-url=https://web.archive.org/web/20190711092009/https://www.bbc.com/news/business-48619804|url-status=live}}

In December 2019, multiple Russian businessmen suffered account takeovers that involved bypassing SMS single-factor authentication. Security company Group-IB suggested SS7 mobile signalling protocol weaknesses, illegal usage of surveillance equipment, or telecom insider attacks.{{cite web|url=https://www.forbes.com/sites/thomasbrewster/2019/12/12/mystery-russian-telegram-hacks-intercept-secret-codes-to-spy-on-messages/|title=Mystery Russian Telegram Hacks Intercept Secret Codes To Spy On Messages|last=Brewster|first=Thomas|website=Forbes|language=en|access-date=13 December 2019|archive-date=1 November 2020|archive-url=https://web.archive.org/web/20201101071209/https://www.forbes.com/sites/thomasbrewster/2019/12/12/mystery-russian-telegram-hacks-intercept-secret-codes-to-spy-on-messages/|url-status=live}}{{cite web|url=https://tvrain.ru/news/group_ib_rossijskie_predprinimateli_pozhalovalis_na_vzlom_perepiski_v_telegram-498660/|title=Group-IB: российские предприниматели пожаловались на взлом переписки в Telegram|author=((TV Rain Inc.))|date=4 December 2019|website=tvrain.ru|language=ru|access-date=13 December 2019|archive-date=13 August 2020|archive-url=https://web.archive.org/web/20200813061736/https://tvrain.ru/news/group_ib_rossijskie_predprinimateli_pozhalovalis_na_vzlom_perepiski_v_telegram-498660/|url-status=live}}

On 30 March 2020, an Elasticsearch database holding 42 million records containing user IDs and phone numbers of Iranian users was exposed online without a password. The accounts were extracted from not Telegram but an unofficial version of Telegram, in what appears to be a possibly government-sanctioned fork. It took 11 days for the database to be taken down, but the researchers say the data was accessed by other parties, including a hacker who reported the information to a specialized forum.{{cite web|url=https://www.comparitech.com/blog/information-security/iranian-telegram-accounts-leaked/|title=Report: 42M Iranian "Telegram" User IDs & Phone Numbers Leaked Online|date=30 March 2020|website=Comparitech|language=en-US|access-date=8 April 2020|archive-date=4 December 2020|archive-url=https://web.archive.org/web/20201204071119/https://www.comparitech.com/blog/information-security/iranian-telegram-accounts-leaked/|url-status=live}}{{cite web|url=https://securityboulevard.com/2020/04/elasticsearch-database-with-42-million-records-of-iranian-citizen-found-exposed-online/|title=Elasticsearch Database with 42 Million Records of Iranian Citizen Found Exposed Online|last1=Stahie|first1=Silviu|date=7 April 2020|website=Security Boulevard|language=en-US|access-date=8 April 2020|archive-date=6 December 2020|archive-url=https://web.archive.org/web/20201206113852/https://securityboulevard.com/2020/04/elasticsearch-database-with-42-million-records-of-iranian-citizen-found-exposed-online/|url-status=live}}{{cite web|url=https://hotforsecurity.bitdefender.com/blog/elasticsearch-database-with-42-million-records-of-iranian-citizen-found-exposed-online-22852.html|title=Elasticsearch Database with 42 Million Records of Iranian Citizen...|last=Stahie|first=Silviu|date=7 April 2020|website=HOTforSecurity|language=en-US|access-date=8 April 2020|archive-date=24 October 2020|archive-url=https://web.archive.org/web/20201024205102/https://hotforsecurity.bitdefender.com/blog/elasticsearch-database-with-42-million-records-of-iranian-citizen-found-exposed-online-22852.html|url-status=live}}

In September 2020, it was reported that Iran's RampantKitten espionage group ran a phishing and surveillance campaign against dissidents on Telegram.{{Cite web|url=https://blog.checkpoint.com/2020/09/18/rampantkitten-an-iranian-surveillance-operation-unraveled/|title=RampantKitten: An Iranian Surveillance Operation unraveled|date=18 September 2020|website=Check Point Software|access-date=19 September 2020|archive-date=28 October 2020|archive-url=https://web.archive.org/web/20201028174133/https://blog.checkpoint.com/2020/09/18/rampantkitten-an-iranian-surveillance-operation-unraveled/|url-status=live}} The attack relied on people downloading a malware-infected file from any source, at which point it would replace Telegram files on the device and 'clone' session data. David Wolpoff, a former Department of Defense contractor, has stated that the weak link in the attack was the device itself and not any of the affected apps: "There's no way for a secure communication app to keep a user safe when the end devices are compromised."{{cite web|url=https://www.securitymagazine.com/articles/93423-check-point-researchers-Iranian-hackers-can-bypass-encrypted-apps-like-telegram|title=Check Point researchers: Iranian hackers can bypass encrypted apps like Telegram|date=22 September 2020|website=Security Magazine|language=en-US|access-date=25 September 2020|archive-date=22 October 2020|archive-url=https://web.archive.org/web/20201022205723/https://www.securitymagazine.com/articles/93423-check-point-researchers-Iranian-hackers-can-bypass-encrypted-apps-like-telegram|url-status=live}}

In July 2021, researchers from Royal Holloway, University of London and ETH Zurich published an analysis of the MTProto protocol, concluding that the protocol could provide a "confidential and integrity-protected channel" for communication. They also found that attackers had the theoretical ability to reorder messages coming from the client to the server though the attacker would not be able to see the content of the messages. Several other theoretical vulnerabilities were reported as well, in response to which Telegram released a document stating that the MITM attack on the key exchange was impossible as well as detailing the changes made to the protocol to protect from it in the future. All issues were patched before the paper's publication with a security bounty paid out to the researchers.{{cite web |url=https://mtpsym.github.io/ |title=Security Analysis of Telegram (Symmetric Part) |date=16 July 2021 |website=Github |language=en |access-date=16 July 2021 |url-status=live |archive-date=16 July 2021 |archive-url=https://web.archive.org/web/20210716090326/https://mtpsym.github.io/ }}{{cite web |url=https://core.telegram.org/techfaq/UoL-ETH-4a-proof |title=MTProto Analysis: Comments for the technically inclined |date=16 July 2021 |website=Telegram |language=en |access-date=16 July 2021 |url-status=live |archive-date=16 July 2021 |archive-url=https://web.archive.org/web/20210716145120/https://core.telegram.org/techfaq/UoL-ETH-4a-proof }}{{cite web |url=https://www.cyberscoop.com/telegram-app-security-encryption/ |title=Cryptographers unearth vulnerabilities in Telegram's encryption protocol |date=16 July 2021 |website=Cyberscoop |language=en |access-date=16 July 2021 |url-status=live |archive-date=16 July 2021 |archive-url=https://web.archive.org/web/20210716145127/https://www.cyberscoop.com/telegram-app-security-encryption/ }}

In September 2021, a Russian researcher published details about a bug with the self-destruct feature that allowed the user to recover deleted photos from their own device. The bug was patched prior to publication and Telegram representatives offered a €1,000 bug bounty. The researcher did not sign the NDA that came with the offer and did not receive the award, opting to disclose the bug.{{cite web |last=Sharma |first=Ax |url=https://arstechnica.com/information-technology/2021/10/researcher-refuses-telegrams-bounty-award-discloses-auto-delete-bug/ |title=Researcher refuses Telegram's bounty award, discloses auto-delete bug |date=4 October 2021 |website=ArsTechnica |language=en |access-date=8 October 2021 |url-status=live |archive-date=8 October 2021 |archive-url=https://web.archive.org/web/20211008082339/https://arstechnica.com/information-technology/2021/10/researcher-refuses-telegrams-bounty-award-discloses-auto-delete-bug/ }}{{Cite web|title=Конфиденциальность пользователей Telegram снова нарушена. Представители мессенджера требуют не раскрывать подробностей|url=https://habr.com/ru/post/580582/|access-date=8 October 2021|website=habr.com|date=29 September 2021 |language=en|archive-date=7 October 2021|archive-url=https://web.archive.org/web/20211007215311/https://habr.com/ru/post/580582/|url-status=live}}{{Cite news|title=bug bounty EUR1,000.pdf|url=https://drive.google.com/file/d/13sEnr37gFw2ygsnDHLYbPloiAtvhR59X/view?usp=sharing&usp=embed_facebook|access-date=8 October 2021|website=Google Docs|archive-date=7 October 2021|archive-url=https://web.archive.org/web/20211007011725/https://drive.google.com/file/d/13sEnr37gFw2ygsnDHLYbPloiAtvhR59X/view?usp=sharing&usp=embed_facebook|url-status=live}}{{Cite web|title=NVD – CVE-2021-41861|url=https://nvd.nist.gov/vuln/detail/CVE-2021-41861|access-date=8 October 2021|website=nvd.nist.gov|archive-date=8 October 2021|archive-url=https://web.archive.org/web/20211008064513/https://nvd.nist.gov/vuln/detail/CVE-2021-41861|url-status=live}}

In March 2023, the Norwegian National Security Authority (NSM) advised against the use of Telegram and TikTok on business devices (especially the ones used for government related activities), the assessment has been commissioned and supported by the Ministry of Justice and Public Security, Emilie Enger Mehl. Regarding Telegram, the report cites its lack of end-to-end encryption by default, its Russian origins and third-party open source intelligence as major critical points.{{Cite web |url=https://nsm.no/aktuelt/anbefaler-ikke-tiktok-eller-telegram-pa-tjenesteenheter |title=Anbefaler ikke Tiktok eller Telegram på tjenesteenheter |date=23 March 2023 |access-date=26 March 2023 |website=Nasjonal sikkerhetsmyndighet |archive-url=https://archive.today/20230326201653/https://nsm.no/aktuelt/anbefaler-ikke-tiktok-eller-telegram-pa-tjenesteenheter |archive-date=26 March 2023 |url-status=live |language=no |trans-title=Do not recommend Tiktok or Telegram on service devices}}

In July 2024, ESET reported a vulnerability allowed malicious files being sent to users masked in multimedia.{{cite web | url=https://www.welivesecurity.com/en/eset-research/cursed-tapes-exploiting-evilvideo-vulnerability-telegram-android/ | title=Cursed tapes: Exploiting the EvilVideo vulnerability on Telegram for Android }}

Telegram has organized two cryptography contests to challenge its own security. Third parties were asked to break the service's cryptography and disclose the information contained within a secret chat between two computer-controlled users. A reward of respectively {{US$|200000}} and {{US$|300000}} was offered. Both of these contests expired with no winners.{{cite web|url = https://telegram.org/blog/winter-contest-ends|title = Winter Contest Ends|date = 2 March 2014|access-date = 24 October 2015|website = Telegram|archive-date = 26 December 2018|archive-url = https://web.archive.org/web/20181226140739/https://telegram.org/blog/winter-contest-ends%20|url-status = live}}{{cite web|url = https://telegram.org/blog/cryptocontest-ends|title = Crypto Contest Ends|date = 11 February 2015|access-date = 24 October 2015|website = Telegram|archive-date = 18 May 2019|archive-url = https://web.archive.org/web/20190518221134/https://telegram.org/blog/cryptocontest-ends|url-status = live}}

Security researcher Moxie Marlinspike, founder of the competing Signal messenger, and commenters on Hacker News criticized the first contest for being rigged or framed in Telegram's favor and said that Telegram's statements on the value of these contests as proof of the cryptography's quality are misleading. This was because the cryptography contest could not be won even with completely broken algorithms such as MD2 (hash function) used as key stream extractor, and primitives such as the Dual EC DRBG that is known to be backdoored.{{cite web|url = http://thoughtcrime.org/blog/telegram-crypto-challenge/|archive-url = https://archive.today/20131219191437/http://thoughtcrime.org/blog/telegram-crypto-challenge/|url-status=dead|archive-date = 19 December 2013|title = A Crypto Challenge for the Telegram Developers|first = Moxie|last = Marlinspike|date = 19 December 2013|work = Thought Crime|access-date = 2 March 2014|author-link = Moxie Marlinspike|df = dmy-all}}{{cite web|url = http://tech.eu/news/telegram-protocol-cracking-contest/|title = Cracking contest: first one who breaks Telegram gets $200,000 in bitcoins (but really, nobody wins)|first = Robin|last = Wauters|date = 19 December 2013|access-date = 2 March 2014|website = Tech.eu|archive-date = 26 December 2018|archive-url = https://web.archive.org/web/20181226140728/https://tech.eu/news/telegram-protocol-cracking-contest/|url-status = live}}{{cite news|url = http://www.cryptofails.com/post/70546720222/telegrams-cryptanalysis-contest|title = Telegram's Cryptanalysis Contest|date = 19 December 2013|access-date = 24 October 2015|newspaper = Tumblr|last = Hornby|first = Taylor|archive-date = 26 December 2018|archive-url = https://web.archive.org/web/20181226140737/http://www.cryptofails.com/post/70546720222/telegrams-cryptanalysis-contest|url-status = live}}

{{Further|Government censorship of Telegram}}

File:Telegram-World.svg

Telegram has been blocked temporarily or permanently by some governments including Iran, China, Brazil, and Pakistan. The Russian government blocked Telegram for several years before lifting the ban in 2020.{{Cite news |last=Erdbrink |first=Thomas |date=1 May 2018 |title=Iran, Like Russia Before It, Tries to Block Telegram App |language=en-US |work=The New York Times |url=https://www.nytimes.com/2018/05/01/world/middleeast/iran-telegram-app-russia.html |url-status=live |access-date=27 June 2021 |archive-url=https://web.archive.org/web/20201106232828/https://www.nytimes.com/2018/05/01/world/middleeast/iran-telegram-app-russia.html |archive-date=6 November 2020 |issn=0362-4331}}{{Cite web |date=18 June 2020 |title=Russia lifts ban on private messaging app Telegram |url=https://www.independent.co.uk/news/world/europe/telegram-russia-ban-lift-messaging-app-encryption-download-a9573181.html |url-status=live |archive-url=https://web.archive.org/web/20201107020625/https://www.independent.co.uk/news/world/europe/telegram-russia-ban-lift-messaging-app-encryption-download-a9573181.html |archive-date=7 November 2020 |access-date=27 June 2021 |website=The Independent |language=en}}{{Cite web |last=Kilpatrick |first=Ryan Ho |date=13 July 2015 |title=China blocks Telegram messenger, blamed for aiding human rights lawyers |url=https://hongkongfp.com/2015/07/13/china-blocks-telegram-messenger-blamed-for-aiding-human-rights-lawyers/ |url-status=live |archive-url=https://archive.today/20150713082315/https://www.hongkongfp.com/2015/07/13/china-blocks-telegram-messenger-blamed-for-aiding-human-rights-lawyers/ |archive-date=13 July 2015 |access-date=27 June 2021 |website=Hong Kong Free Press HKFP |language=en-GB}} The company's founder has said he wants the app to have an anti-censorship tool for Iran and China similar to the app's role in fighting censorship in Russia.{{Cite web |title=Telegram founder says anti-censorship tech that defeated Russian authorities should be used against Iran and China |url=https://meduza.io/en/news/2020/06/22/telegram-founder-says-anti-censorship-tech-used-to-defeat-russian-authorities-should-be-used-in-iran-and-china |url-status=live |archive-url=https://web.archive.org/web/20210613170350/https://meduza.io/en/news/2020/06/22/telegram-founder-says-anti-censorship-tech-used-to-defeat-russian-authorities-should-be-used-in-iran-and-china |archive-date=13 June 2021 |access-date=27 June 2021 |website=Meduza |language=en}} On 19 April 2024, Apple removed Telegram from the App Store in China.{{cite web |last1=Lomas |first1=Natasha |title=Apple pulls WhatsApp, Threads from China App Store following state order |url=https://techcrunch.com/2024/04/19/threads-whatsapp-removed-from-china-app-store/ |website=TechCrunch |access-date=19 April 2024 |date=19 April 2024}}

In September 2024, Ukraine banned the usage of Telegram by government officials, military personnel, and key workers on official devices, citing fears of Russian espionage. The National Security and Defense Council of Ukraine enforced the restrictions following evidence reported to them by Kyrylo Budanov, showing Russia's ability to access messages and user data on the platform. Andriy Kovalenko, head of the security council's centre on countering disinformation, clarified that the ban was limited to official devices and did not extend to personal phones.{{cite news|title=Ukraine bans official use of Telegram app over fears of Russian spying |date=20 September 2024 |url=https://www.reuters.com/technology/cybersecurity/ukraine-bans-official-use-telegram-app-over-fears-russian-spying-2024-09-20/ |access-date=22 September 2024}}

{{Main|Telegramgate}}

Telegram was the main subject surrounding the 2019 Puerto Rico riots that ended up in the resignation of then-Governor Ricardo Rosselló. Hundreds of pages of a group chat between Rosselló and members of his staff were leaked. The messages were considered vulgar, racist, and homophobic, with members of the chat discussing how they would use the media to target potential political opponents.{{cite web|last=Serrano|first=Oscar J.|title=WhatsApp Gate 2.0: Nuevo chat expone a la Administración Rosselló|url=https://www.noticel.com/ahora/gobierno/whatsapp-gate-20-nuevo-chat-expone-a-la-administracion-rossello/1093250289|website=NotiCel|accessdate=19 July 2019|language=es|date=13 July 2019|archive-date=27 July 2019|archive-url=https://web.archive.org/web/20190727235312/https://www.noticel.com/ahora/gobierno/whatsapp-gate-20-nuevo-chat-expone-a-la-administracion-rossello/1093250289|url-status=dead}}

In September 2021, prior to the regional elections in Russia, Telegram suspended several bots spreading information about the election, including a bot run by the opposition party and critics of incumbent president Vladimir Putin's government,{{Cite web |date=18 September 2021 |title=Telegram Messenger Blocks Navalny's Bot During Vote |url=https://www.rferl.org/a/telegram-navalny-smart-voting/31466263.html |url-status=live |archive-url=https://web.archive.org/web/20210918221938/https://www.rferl.org/a/telegram-navalny-smart-voting/31466263.html |archive-date=18 September 2021 |access-date=19 September 2021 |website=RadioFreeEurope |language=en}}{{Cite web |agency=AFP |date=18 September 2021 |title=Telegram Messenger Blocks Navalny Bot During Russian Election |url=https://www.themoscowtimes.com/2021/09/18/telegram-messenger-blocks-navalny-bot-during-russian-election-a75079 |url-status=live |archive-url=https://web.archive.org/web/20210926151950/https://www.themoscowtimes.com/2021/09/18/telegram-messenger-blocks-navalny-bot-during-russian-election-a75079 |archive-date=26 September 2021 |access-date=26 September 2021 |website=The Moscow Times |language=en}} citing election silence as the reason, though a blog post by the company's CEO implied the company was following Apple and Google, which "dictate the rules of the game to developers".{{Cite web |date=18 September 2021 |title=Telegram messenger blocks Russia opposition bot during vote |url=https://www.rfi.fr/en/business-and-tech/20210918-telegram-messenger-blocks-russia-opposition-bot-during-vote |url-status=live |archive-url=https://web.archive.org/web/20210918153809/https://www.rfi.fr/en/business-and-tech/20210918-telegram-messenger-blocks-russia-opposition-bot-during-vote |archive-date=18 September 2021 |access-date=18 September 2021 |website=RFI |language=en}} The blocking of the main Smart Voting bot was criticized by allies of Alexei Navalny, a Kremlin critic and former opposition leader. Navalny's spokeswoman Kira Yarmysh called the block and the deletion of the tactical voting app from app stores "censorship [...] imposed by private companies".{{Cite web |date=18 September 2021 |title=Navalny allies accuse YouTube, Telegram of censorship in Russian election |url=https://www.reuters.com/world/europe/navalny-allies-accuse-telegram-censorship-russian-election-2021-09-18/ |url-status=live |archive-url=https://web.archive.org/web/20210920012333/https://www.reuters.com/world/europe/navalny-allies-accuse-telegram-censorship-russian-election-2021-09-18/ |archive-date=20 September 2021 |access-date=19 September 2021 |website=Reuters |language=en}}

In a later blog post, Durov directly stated that the block was a result of pressure from Google and Apple as refusal to comply with their policies would result "in an immediate shutdown of Telegram for millions of users". The post included a screenshot showing an internal email sent by the App Store to developers, demanding the takedown of content related to Navalny.{{Cite web |title=Durov's Channel |url=https://t.me/durov/168 |url-status=live |archive-url=https://web.archive.org/web/20210926010611/https://t.me/durov/168 |archive-date=26 September 2021 |access-date=28 September 2021 |website=Telegram |language=en-US}}

On 24 November 2022, Telegram disclosed the admin names, phone numbers and IP addresses of channels accused of unauthorised sharing of national exam study materials following an order by the Delhi High Court which rejected Telegram's argument that its regional servers were located in Singapore and thus no data could be disclosed as the local laws prohibit it.{{Cite court|litigants=Neetu Singh vs Telegram FZ LLC|court=High Court of Delhi at New Dehli|date=24 November 2022|url=http://164.100.60.183/writereaddata/orderSan_Pdf/pms/2022/1669618366215_31241_2022.pdf|archive-url=https://web.archive.org/web/20231204014758/http://164.100.60.183/writereaddata/orderSan_Pdf/pms/2022/1669618366215_31241_2022.pdf|url-status=bot: unknown}}{{cite news |last1=Ahsan |first1=Sofi |date=29 November 2022 |title=After Delhi High Court Ruling, Telegram Discloses Names, Phone Numbers & IP Addresses Of Users Accused Of Sharing Infringing Material |url=https://www.livelaw.in/news-updates/after-court-order-telegram-discloses-phone-numbers-ip-addresses-of-users-accused-of-sharing-infringing-material-215311 |url-access=subscription |access-date=27 August 2024 |work=LiveLaw}}

{{Main|Arrest of Pavel Durov}}

On 24 August 2024, Pavel Durov, who is both a French and UAE citizen, was arrested in France by French authorities and four days later charged with a wide array of crimes, including complicity in managing an online platform to enable illegal transactions; complicity in crimes such as enabling the distribution of child sexual abuse material; drug trafficking and fraud; and a refusal to cooperate with law enforcement authorities. Durov posted bail of five million Euros, was barred from leaving France, and was released on condition he report to a French police station twice weekly. The case would be handled by a special magistrate with investigative and prosecutorial powers.{{cite news |last1=Dalton |first1=Matthew |title=French Authorities Charge Telegram Founder Pavel Durov |url=https://www.wsj.com/tech/telegram-ceo-pavel-durov-charged-french-authorities-43a125a2?mod=hp_lead_pos8 |access-date=28 August 2024 |agency=The Wall Street Journal |publisher=Dow Jones and Company}}

• Alt-tech
• Comparison of cross-platform instant messaging clients
• Internet privacy
• Secure instant messaging

{{clear}}

{{reflist}}

• {{cite web|url=https://www.usenix.org/system/files/conference/foci17/foci17-paper-espinoza.pdf|title=Alice and Bob, who the FOCI are they?: Analysis of end-to-end encryption in the LINE messaging application|last1=Espinoza|first1=Antonio|last2=Tolley|first2=William|date=August 2017|website=Usenix|publisher=USENIX Association|access-date=12 May 2021|ref={{harvid|Espinoza|Tolley|Crandall|2017}}|archive-date=11 May 2021|archive-url=https://web.archive.org/web/20210511230541/https://www.usenix.org/system/files/conference/foci17/foci17-paper-espinoza.pdf|url-status=live}}
• {{Cite conference|last1=Rottermanner|first1=Christoph|last2=Kieseberg|first2=Peter|last3=Huber|first3=Markus|last4=Schmiedecker|first4=Martin|last5=Schrittwieser|first5=Sebastian|date=December 2015|title=Privacy and Data Protection in Smartphone Messengers|url=https://www.sba-research.org/wp-content/uploads/publications/paper_drafthp.pdf|conference=Proceedings of the 17th International Conference on Information Integration and Web-based Applications & Services (iiWAS2015)|publisher=ACM International Conference Proceedings Series|isbn=978-1-4503-3491-4|access-date=18 March 2016|archive-date=27 March 2016|archive-url=https://web.archive.org/web/20160327011416/https://www.sba-research.org/wp-content/uploads/publications/paper_drafthp.pdf|url-status=live}}

{{Refbegin|30em}}

• {{cite web|url=https://eprint.iacr.org/2015/1177.pdf|title=On the CCA (in)security of MTProto|last1=Jakobsen|first1=Jakob|last2=Orlandi|first2=Claudio|date=8 December 2015|website=Cryptology ePrint Archive|publisher=International Association for Cryptologic Research (IACR)|access-date=11 December 2015|archive-date=12 December 2015|archive-url=https://web.archive.org/web/20151212214527/http://eprint.iacr.org/2015/1177.pdf|url-status=live}}
• {{cite arXiv|title=Automated Symbolic Verification of Telegram's MTProto 2.0|last1=Miculan|first1=Marino|last2=Vitocolonna|first2=Nicola|date=5 December 2020|class=cs.CR |eprint=2012.03141v1}}
• {{cite web|url=https://mtpsym.github.io/paper.pdf|title=Four Attacks and a Proof for Telegram|last1=Albrecht|first1=Martin R.|last2=Mareková|first2=Lenka|last3=Paterson|first3=Kenneth G.|last4=Stepanovs|first4=Igors|date=16 July 2021|access-date=16 July 2021|archive-date=16 July 2021|archive-url=https://web.archive.org/web/20210716091205/https://mtpsym.github.io/paper.pdf|url-status=live}}
• {{cite web|last1=Abu-Salma|first1=Ruba|last2=Krol|first2=Kat|last3=Parkin|first3=Simon|last4=Kohl|first4=Victoria|last5=Kwan|first5=Kevin|last6=Mahboob|first6=Jazib|last7=Traboulsi|first7=Zahra|last8=Sasse|first8=M. Angela|url=https://discovery.ucl.ac.uk/id/eprint/1560501/1/Abu-Salma%20et%20al.%20-%202017%20-%20The%20Security%20Blanket%20of%20the%20Chat%20World%20An%20Analyti.pdf|title=The Security Blanket of the Chat World:An Analytic Evaluation and a User Study of Telegram|publisher=University College London|journal=|access-date=7 February 2021|archive-date=5 February 2021|archive-url=https://web.archive.org/web/20210205025259/https://discovery.ucl.ac.uk/id/eprint/1560501/1/Abu-Salma%20et%20al.%20-%202017%20-%20The%20Security%20Blanket%20of%20the%20Chat%20World%20An%20Analyti.pdf|url-status=live}}
• {{cite web|last1=Hannan Bin Azhar|first1=M A|last2=Barton|first2=Thomas Edward Allen|url=https://repository.canterbury.ac.uk/download/3e59ded778529baaf67e0be4d5c9b31b7fca48bb14ef965948fa5cc6d578c3c6/685125/15054.pdf|title=Forensic Analysis of Secure Ephemeral Messaging Applications on Android Platforms|publisher=Canterbury Christ Church University|journal=|access-date=7 February 2021|archive-date=27 June 2021|archive-url=https://web.archive.org/web/20210627152104/https://repository.canterbury.ac.uk/download/3e59ded778529baaf67e0be4d5c9b31b7fca48bb14ef965948fa5cc6d578c3c6/685125/15054.pdf|url-status=live}}

{{Refend}}

{{Wikidata property | P3789 }}

• {{Official website}}

{{Instant messaging}}

{{Authority control}}

{{Subject bar|commons=y|s-search=|portal3=Freedom of speech|portal2=internet|portal1=companies|d-search=|d=y|v-search=|v=y|s=y|commons-search=Category:Telegram Messenger|q-search=|q=y|b-search=|b=y|wikt-search=|wikt=y|n-search=|n=y|portal4=Telecommunications|portal5=Free and open-source software}}

Category:2013 software

Category:Alt-tech

Category:Communication software

Category:Cross-platform software

Category:End-to-end encryption

Category:Free and open-source Android software

Category:Instant messaging clients

Category:Internet properties established in 2013

Category:IOS software

Category:Linux software

Category:Russian inventions

Category:Software that uses Qt

Category:Windows Phone software