HTTP/3
{{Short description|Layer 7 network protocol published in 2022}}
{{Infobox protocol
| standard = {{IETF RFC|9114}}{{Ref RFC|9114}} (HTTP/3 also uses the completed QUIC protocol described in RFC 9000 and related RFCs such as RFC 9001)
| developer = IETF
| introdate = June 2022
| newer =
}}
{{Internet history timeline}}
HTTP/3 is the third major version of the Hypertext Transfer Protocol used to exchange information on the World Wide Web, complementing the widely deployed HTTP/1.1 and HTTP/2. Unlike previous versions which relied on the well-established TCP (published in 1974),{{Ref RFC|675}} HTTP/3 uses QUIC (officially introduced in 2021),{{Ref RFC|9000}} a multiplexed transport protocol built on UDP.{{Cite web |date= |title=What is HTTP/3? |url=https://www.cloudflare.com/learning/performance/what-is-http3/ |url-status=live |archive-url=https://web.archive.org/web/20220704035921/https://www.cloudflare.com/learning/performance/what-is-http3/ |archive-date=4 July 2022 |access-date=12 July 2022 |website=Cloudflare}}
HTTP/3 uses similar semantics compared to earlier revisions of the protocol, including the same request methods, status codes, and message fields, but encodes them and maintains session state differently. However, partially due to the protocol's adoption of QUIC, HTTP/3 has lower latency and loads more quickly in real-world usage when compared with previous versions: in some cases over four times as fast than with HTTP/1.1 (which, for many websites, is the only HTTP version deployed).{{Cite journal |last1=Perna |first1=Gianluca |last2=Trevisan |first2=Martino |last3=Giordano |first3=Danilo |last4=Drago |first4=Idilio |date=2022-04-01 |title=A first look at HTTP/3 adoption and performance |url=https://www.sciencedirect.com/science/article/pii/S0140366422000421 |journal=Computer Communications |language=en |volume=187 |pages=115–124 |doi=10.1016/j.comcom.2022.02.005 |s2cid=246936473 |issn=0140-3664|hdl=11368/3025202 |hdl-access=free }}{{Cite web |title=HTTP/3 is Fast |url=https://requestmetrics.com/web-performance/http3-is-fast |access-date=2022-07-01 |website=Request Metrics |language=en}}
As of September 2024, HTTP/3 is supported by more than 95% of major web browsers in use and 34% of the top 10 million websites.{{cite web|title=Usage of HTTP/3 for websites|url=https://w3techs.com/technologies/details/ce-http3|access-date=11 August 2024|website=World Wide Web Technology Surveys|publisher=W3Techs}} It has been supported by Chromium (and derived projects including Google Chrome, Microsoft Edge, Samsung Internet, and Opera){{Cite web|title=Enabling QUIC in tip-of-tree|url=https://groups.google.com/a/chromium.org/g/net-dev/c/5M9Z5mtvg_Y/m/iw9co1VrBQAJ|access-date=2021-04-08|website=groups.google.com}} since April 2020 and by Mozilla Firefox since May 2021.{{Cite web|last=Damjanovic|first=Dragana|date=16 April 2021|title=QUIC and HTTP/3 Support now in Firefox Nightly and Beta|url=https://hacks.mozilla.org/2021/04/quic-and-http-3-support-now-in-firefox-nightly-and-beta|access-date=2021-04-17|website=Mozilla Hacks – the Web developer blog|language=en-US}} Safari 14 implemented the protocol but it remains disabled by default.{{Cite web|title=Safari 14 Release Notes|url=https://developer.apple.com/documentation/safari-release-notes/safari-14-release-notes|access-date=4 December 2020|website=developer.apple.com}}
History
file:HTTP-1.1 vs. HTTP-2 vs. HTTP-3 Protocol Stack.svg|frame|Protocol stack of HTTP/3 compared to HTTP/1.1 and HTTP/2
rect 0 44 85 94 HTTP/1
rect 0 95 85 137 Transport Layer Security
rect 0 138 85 189 Transmission Control Protocol
rect 126 44 210 94 HTTP/2
rect 126 95 210 137 TLS 1.2
rect 126 138 210 189 Transmission Control Protocol
rect 251 44 336 74 HTTP/3
rect 255 90 328 121 TLS 1.3
rect 251 125 336 158 QUIC
rect 251 159 336 189 User Datagram Protocol
rect 0 189 336 231 Internet Protocol
HTTP/3 originates from an Internet Draft adopted by the QUIC working group. The original proposal was named "HTTP/2 Semantics Using The QUIC Transport Protocol",{{Cite IETF|title=HTTP/2 Semantics Using The QUIC Transport Protocol|draft=draft-shade-quic-http2-mapping|last=Shade|first=Robbie|date=8 July 2016|publisher=IETF}} and later renamed "Hypertext Transfer Protocol (HTTP) over QUIC".{{Cite news|last=Cimpanu|first=Catalin|date=12 November 2018|title=HTTP-over-QUIC to be renamed HTTP/3|language=en|work=ZDNet|url=https://www.zdnet.com/article/http-over-quic-to-be-renamed-http3/|access-date=12 November 2018}}
On 28 October 2018 in a mailing list discussion, Mark Nottingham, Chair of the IETF HTTP and QUIC Working Groups, proposed renaming HTTP-over-QUIC to HTTP/3, to "clearly identify it as another binding of HTTP semantics to the wire protocol [...] so people understand its separation from QUIC".{{Cite journal|last=Nottingham|first=Mark|date=28 October 2018|title=Identifying our deliverables|url=https://mailarchive.ietf.org/arch/msg/quic/RLRs4nB1lwFCZ_7k0iuz0ZBa35s|journal=IETF Mail Archive}} Nottingham's proposal was accepted by fellow IETF members a few days later. The HTTP working group was chartered to assist the QUIC working group during the design of HTTP/3, then assume responsibility for maintenance after publication.{{Cite web|title=Hypertext Transfer Protocol Charter|url=https://datatracker.ietf.org/doc/charter-ietf-httpbis/08/|access-date=2020-09-02|website=ietf.org}}
Support for HTTP/3 was added to Chrome (Canary build) in September 2019 and then eventually reached stable builds, but was disabled by a feature flag. It was enabled by default in April 2020. Firefox added support for HTTP/3 in November 2019 through a feature flag{{Cite web |title="HTTP/3" {{!}} Can I use... Support tables for HTML5, CSS3, etc |url=https://caniuse.com/http3 |access-date=2024-08-11 |website=canIuse.com}}{{cite web|last1=Daniel|first1=Stenberg|title=Daniel Stenberg announces HTTP/3 support in Firefox Nightly|url=https://twitter.com/bagder/status/1191482712739196928|access-date=5 November 2019|website=Twitter}}{{cite web|last=Cimpanu|first=Catalin|date=26 Sep 2019|title=Cloudflare, Google Chrome, and Firefox add HTTP/3 support|url=https://www.zdnet.com/article/cloudflare-google-chrome-and-firefox-add-http3-support/|access-date=27 Sep 2019|website=ZDNet|df=dmy-all}} and started enabling it by default in April 2021 in Firefox 88. Experimental support for HTTP/3 was added to Safari Technology Preview on April 8, 2020{{Cite web|url=https://webkit.org/blog/10264/release-notes-for-safari-technology-preview-104/|title=Release Notes for Safari Technology Preview 104|date=8 April 2020|access-date=7 August 2020|website=webkit.org}} and was included with Safari 14 that ships with iOS 14 and macOS 11,{{Cite web|title=Apple's Safari Adds Support for HTTP3 in iOS 14 and macOS 11|url=https://www.iphoneincanada.ca/news/apple-safari-http3-ios-14/|date=23 June 2020|access-date=25 June 2021|website=iphoneincanada.ca|last=Ng|first=Gary}} but it's still disabled by default as of Safari 16, on both macOS and iOS.{{Citation needed|date=October 2022}}
On 6 June 2022, IETF published HTTP/3 as a Proposed Standard in {{IETF RFC|9114}}.{{Ref RFC|9114}}
Comparison with HTTP/1.1 and HTTP/2
HTTP semantics are consistent across versions: the same request methods, status codes, and message fields are typically applicable to all versions. The differences are in the mapping of these semantics to underlying transports. Both HTTP/1.1 and HTTP/2 use TCP as their transport. HTTP/3 uses QUIC, a transport layer network protocol which uses user space congestion control over the User Datagram Protocol (UDP). The switch to QUIC aims to fix a major problem of HTTP/2 called "head-of-line blocking": because the parallel nature of HTTP/2's multiplexing is not visible to TCP's loss recovery mechanisms, a lost or reordered packet causes all active transactions to experience a stall regardless of whether that transaction was impacted by the lost packet. Because QUIC provides native multiplexing, lost packets only impact the streams where data has been lost.
The HTTPS DNS resource record as defined in {{IETF RFC|9460}}{{Ref RFC|9460}} allows for connecting without first receiving the Alt-Svc header via previous HTTP versions, therefore removing the 1 RTT of handshaking of TCP.{{cite web|url=https://developer.mozilla.org/en-US/docs/Glossary/https_rr|accessdate=2022-10-25|title=HTTPS RR|website=MDN|publisher=Mozilla}}{{Cite IETF|title=Service binding and parameter specification via the DNS|draft=draft-ietf-dnsop-svcb-https|first1=Benjamin M.|last1=Schwartz|first2=Mike|last2=Bishop|first3=Erik|last3=Nygren|date=2020-06-12|publisher=IETF}} There is client support for HTTPS resource records since Firefox 92, iOS 14, reported Safari 14 support, and Chromium supports it behind a flag.{{cite web|url=https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/92|accessdate=2022-10-25|title=Firefox 92 for developers|date=7 September 2021|publisher=Mozilla Corporation}}{{cite web|url=https://chromestatus.com/feature/5485544526053376|accessdate=2022-10-25|title=Feature: HTTP->HTTPS redirect for HTTPS DNS records|publisher=Google Inc.}}{{cite web|url=https://serverfault.com/questions/1075522/whats-the-use-case-of-svcb-type-65-service-binding-rr|accessdate=2022-10-25|title=What's the use case of SVCB (type 65, service binding) RR|date=24 August 2021|author1=Patrick Mevzek|publisher=Stack Exchange Inc.}}
Implementations
= Client =
| class="wikitable"
|+ Browser support for HTTP/3 !Browser ! colspan="2" |Version implemented (disabled by default) ! colspan="2" |Version shipped (enabled by default) !Comment |
| Chrome
|Stable build (79) |December 2019 |Earlier versions implemented other drafts of QUIC |
| Edge
|Stable build (79) |December 2019 |87 |April 2020 |Edge 79 was the first version based on Chromium |
| Firefox
|Stable build (72.0.1) |January 2020 | |
| Safari
|Stable build (14.0) |September 2020 |16.4 |March 2023 |Apple is testing HTTP/3 support on some Safari users starting with Safari 16.4.{{Cite web |author=Jen Simmons|date=2023-04-04 |title=HTTP/3 support shipped in Safari 14.0|url=https://github.com/Fyrd/caniuse/pull/6664#issuecomment-1496439786 |access-date=2023-04-07 |website=GitHub}} |
= Libraries =
Open-source libraries that implement client or server logic for QUIC and HTTP/3 include{{Cite web|title=QUIC Implementations|url=https://github.com/quicwg/base-drafts/wiki/Implementations|access-date=2021-04-08|website=GitHub|language=en}}
| class="wikitable sortable"
|+ Libraries implementing HTTP/3 !Name !Client !Server !Programming language !Company !Repository |
| lsquic
|{{yes}} |{{yes}} |C |https://github.com/litespeedtech/lsquic |
| nghttp3
|{{yes}} |{{yes}} |C | |https://github.com/ngtcp2/nghttp3 |
| h2o
|{{no}} |{{yes}} |C | |https://github.com/h2o/h2o |
| libcurl{{Cite web|url=https://daniel.haxx.se/blog/2019/08/05/first-http-3-with-curl/|title=First HTTP/3 with curl|date=August 5, 2019|publisher=Daniel Stenberg|access-date=October 2, 2019}}{{Cite web|url=https://github.com/curl/curl/blob/master/docs/HTTP3.md|title=HTTP3 (and QUIC)|date=August 23, 2023|publisher=Daniel Stenberg|access-date=August 27, 2023}}
|{{yes}} |{{no}} |C | |https://github.com/curl/curl |
| MsQuic{{Cite web|url=https://techcommunity.microsoft.com/t5/networking-blog/msquic-is-open-source/ba-p/1345441|title=MsQuic is Open Source|date=April 28, 2020|access-date=April 28, 2020}}
|{{yes}} |{{yes}} |C |https://github.com/microsoft/msquic |
| proxygen
|{{yes}} |{{yes}} |C++ |https://github.com/facebook/proxygen#quic-and-http3 |
| Cronet
|{{yes}} |{{yes}} |C++ |https://github.com/chromium/chromium/tree/main/net/quic |
| .NET{{Cite web|url=https://devblogs.microsoft.com/dotnet/http-3-support-in-dotnet-6/|title=HTTP/3 support in .NET 6|date=September 17, 2021|access-date=September 17, 2021}}
|{{yes}} |{{yes}} |https://github.com/dotnet |
| quic-go
|{{yes}} |{{yes}} |Go | |https://github.com/quic-go/quic-go |
| http3
|{{yes}} |{{yes}} |Haskell | |https://github.com/kazu-yamamoto/http3 |
| Kwik
|{{yes}} |{{yes}} |Java | |https://github.com/ptrd/kwik |
| Flupke
|{{yes}} |{{yes}} |Java | |https://bitbucket.org/pjtr/flupke |
| aioquic
|{{yes}} |{{yes}} |Python | |https://github.com/aiortc/aioquic |
| quiche
|{{yes}} |{{yes}} |Rust |https://github.com/cloudflare/quiche |
| neqo
|{{yes}} |{{yes}} |Rust |https://github.com/mozilla/neqo |
| quinn
|{{yes}} |{{yes}} |Rust | |https://github.com/quinn-rs/quinn |
| s2n-quic
|{{yes}} |{{yes}} |Rust |https://github.com/aws/s2n-quic |
= Server =
- On 7 June 2021, LiteSpeed Web Server (and OpenLiteSpeed) 6.0.2 was released and became the first version to enable HTTP/3 by default.{{Cite web|title=LiteSpeed Web Server Release Log - LiteSpeed Technologies|url=https://www.litespeedtech.com/products/litespeed-web-server/release-log|access-date=2022-02-12|website=www.litespeedtech.com|quote=Enable HTTP/3 v1 by default.}}
- Caddy web server v2.6.0 (released 20 September 2022) has HTTP/3 enabled by default.{{Cite web|url=https://github.com/caddyserver/caddy/releases/tag/v2.6.0|title=Release 2.6.0 · caddyserver/caddy|date=2022-09-22|website=Github|language=en-US|access-date=2022-09-20}}
- Nginx supports HTTP/3 since 1.25.0 (released 23 May 2023). A technology preview of nginx with HTTP/3 support was released in June 2020.{{Cite web|date=2020-06-10|title=Introducing a Technology Preview of NGINX Support for QUIC and HTTP/3|url=https://www.nginx.com/blog/introducing-technology-preview-nginx-support-for-quic-http-3/|access-date=2020-06-11|website=NGINX|language=en-US}} Binary packages of nginx with HTTP/3 support have been released in February 2023.{{Cite web|date=2023-02-08|title=Binary Packages Now Available for the Preview NGINX QUIC+HTTP/3 Implementation|url=https://www.nginx.com/blog/binary-packages-for-preview-nginx-quic-http3-implementation/|access-date=2023-03-30|website=NGINX|language=en-US}}
- Cloudflare distributes a patch for nginx that integrates the quiche HTTP/3 library into it.{{Cite web|url=https://blog.cloudflare.com/experiment-with-http-3-using-nginx-and-quiche/|title=Experiment with HTTP/3 using NGINX and quiche|date=2019-10-17|website=The Cloudflare Blog|language=en|access-date=2019-11-09}}
- Microsoft IIS support for HTTP/3 is enabled natively with Windows Server 2022/Windows 11.{{Cite web |last=Tratcher |title=Use ASP.NET Core with HTTP/3 on IIS |url=https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/iis/http3 |access-date=2022-04-29 |website=docs.microsoft.com |language=en-us}}
- HAProxy supports HTTP/3 over QUIC since version 2.6 released on 31 May 2022.{{Cite web|title=Announcing HAProxy 2.6|website=HAProxy Blog|date=31 May 2022 |url=https://www.haproxy.com/blog/announcing-haproxy-2-6/#http-3-over-quic}}{{Cite web|title=QUIC Implementation in HAProxy|website=HAProxyConf video presentation|date=25 January 2023 |url=https://www.youtube.com/watch?v=e2aQBva_HH0}}
- Nimble Streamer supports HTTP/3 since 4.1.8-1{{Cite web|date=2025-02-14|title=HTTP/3 and QUIC support in Nimble Streamer|url=https://softvelum.com/2025/02/http3-quic-support-nimble-streamer/|access-date=2025-02-17|website=NGINX|language=en-US}} for HTTP-based protocols.
See also
{{Portal|Internet}}
- {{annotated link|Fast and Secure Protocol}}
References
{{reflist}}
External links
- {{Official website}}
- {{github|quicwg|IETF QUIC Working Group}}
- [https://http3-explained.haxx.se/ HTTP/3 explained] (Daniel Stenberg)
- [https://caniuse.com/http3 HTTP/3 on canIuse.com]
- [https://github.com/quicwg/base-drafts/wiki/Implementations List of QUIC implementations on the IETF QUIC Working Group Wiki]
{{Web interfaces}}
{{Web browsers|fsp}}
{{Use dmy dates|date=January 2019}}
Category:Hypertext Transfer Protocol