Microsoft Edge Legacy

Microsoft Edge [Legacy] was the default web browser, replacing Internet Explorer 11 and Internet Explorer Mobile.{{cite web|url=https://www.theverge.com/2015/3/24/8284781/internet-explorer-is-slowly-dying|title=Microsoft relegates Internet Explorer to a 'legacy engine' to make way for new browser|publisher=Vox Media|date=March 24, 2015|website=The Verge|first1=Tom|last1=Warren|url-status=live|archive-url=https://web.archive.org/web/20150325061911/http://www.theverge.com/2015/3/24/8284781/internet-explorer-is-slowly-dying|archive-date=March 25, 2015|df=mdy-all}} As its development and release is dependent on the model of Windows as a service, it is not included in Windows 10 Long-Term Servicing Branch/Channel (LTSB/LTSC) builds.{{Cite web|url=https://docs.microsoft.com/en-us/windows/deployment/update/waas-overview|title=Overview of Windows as a service (Windows 10)|publisher=Microsoft|language=en-us|access-date=February 25, 2025|archive-date=August 7, 2019|archive-url=https://web.archive.org/web/20190807224031/https://docs.microsoft.com/en-us/windows/deployment/update/waas-overview|url-status=deviated}}{{Cite web|url=https://www.zdnet.com/article/some-windows-10-enterprise-users-wont-get-microsofts-edge-browser/|title=Some Windows 10 Enterprise users won't get Microsoft's Edge browser|last=Foley|first=Mary Jo|website=ZDNet|language=en|access-date=2019-05-05|archive-date=June 9, 2015|archive-url=https://web.archive.org/web/20150609193057/https://www.zdnet.com/article/some-windows-10-enterprise-users-wont-get-microsofts-edge-browser/|url-status=live}}{{Cite web|url=https://www.computerworld.com/article/3250464/faq-windows-10-ltsb-explained.html|title=FAQ: Windows 10 LTSB explained|last=Keizer|first=Gregg|date=2018-11-29|website=Computerworld|language=en|access-date=2019-05-05|archive-date=March 8, 2019|archive-url=https://web.archive.org/web/20190308004403/https://www.computerworld.com/article/3250464/faq-windows-10-ltsb-explained.html|url-status=live}}

Microsoft initially announced that Edge would support the legacy MSHTML (Trident) browser engine for backward compatibility, but later said that, due to "strong feedback", Edge would use a new engine, while Internet Explorer would continue to provide the legacy engine.{{cite web|url=https://www.neowin.net/news/microsoft-says-ie-11-will-remain-unchanged-from-windows-81-spartan-is-the-future|title=Microsoft says IE 11 will remain unchanged from Windows 8.1, Spartan is the future|date=March 24, 2015|website=Neowin|first1=Brad|last1=Sams|url-status=live|archive-url=https://web.archive.org/web/20150527195435/http://www.neowin.net/news/microsoft-says-ie-11-will-remain-unchanged-from-windows-81-spartan-is-the-future|archive-date=May 27, 2015|df=mdy-all}} The developer toolset features an option to emulate the rendering behavior ("document mode") of Internet Explorer versions 5 to 11.[https://web.archive.org/web/20180527135604/https://docs.microsoft.com/en-us/internet-explorer/ie11-deploy-guide/fix-compat-issues-with-doc-modes-and-enterprise-mode-site-list Microsoft Docs (2017)]{{Cite web|url=https://www.nfc.usda.gov/Publications/HR_Payroll/Reporting/Bulletins/2015/REPT-15-04att.htm|title=Turning Off Compatibility Mode to Use Internet Explorer (IE) 11 with Insight|access-date=February 25, 2025|archive-date=June 15, 2022|archive-url=https://web.archive.org/web/20220615001807/https://www.nfc.usda.gov/Publications/HR_Payroll/Reporting/Bulletins/2015/REPT-15-04att.htm|url-status=live}}

Favorites, reading list, browsing history and downloads are viewed at the Hub,{{cite web|url=https://support.microsoft.com/en-us/help/17171/microsoft-edge-get-to-know|website=support.microsoft.com|title=Get to know Microsoft Edge|url-status=deviated|archive-url=https://web.archive.org/web/20191025122218/https://support.microsoft.com/en-us/help/17171/microsoft-edge-get-to-know|archive-date=October 25, 2019}} a sidebar providing functionality similar to Internet Explorer's Downloads manager and Favorites Center.{{cite web|url=https://learn.microsoft.com/en-gb/archive/blogs/ie/favorites-center|website=Microsoft Learn|title=Favorites Center - IEBlog|date=February 6, 2006|url-status=live|archive-url=https://web.archive.org/web/20180129140617/https://blogs.msdn.microsoft.com/ie/2006/02/06/favorites-center/|archive-date=January 29, 2018|access-date=February 27, 2025}}

Edge features a built-in PDF reader,{{cite web|url=https://www.helpnetsecurity.com/2015/07/31/microsoft-edge-new-browser-new-risks-for-windows-10/|title=Microsoft Edge: New browser, new risks for Windows 10|work=Trend Micro|publisher=Help Net Security|date=July 31, 2015|access-date=February 27, 2025|url-status=live|archive-url=https://web.archive.org/web/20150906012453/http://blog.trendmicro.com/trendlabs-security-intelligence/windows-10s-new-browser-microsoft-edge-improved-but-also-new-risks/|archive-date=September 6, 2015}} and supports WebAssembly. Until January 2021, Edge also featured an integrated Adobe Flash Player (with an internal whitelist allowing Flash applets on Facebook and other websites to load automatically, bypassing all other security controls requiring user activation).{{Cite web|url=https://www.zdnet.com/article/microsoft-edge-lets-facebook-run-flash-code-behind-users-backs/|title=Microsoft Edge lets Facebook run Flash code behind users' backs|last=Cimpanu|first=Catalin|website=ZDNet|language=en|access-date=2019-02-20|archive-date=December 14, 2020|archive-url=https://web.archive.org/web/20201214152529/https://www.zdnet.com/article/microsoft-edge-lets-facebook-run-flash-code-behind-users-backs/|url-status=live}}

Edge does not support legacy technologies such as ActiveX and Browser Helper Objects; instead, it uses an extension system based on the cross-browser WebExtension API.{{cite web|url=https://blogs.windows.com/msedgedev/2014/11/11/living-on-the-edge-our-next-step-in-helping-the-web-just-work/|title=Living on the edge – our next step in helping the web just work|work=Microsoft Edge Team|publisher=Windows Blogs|date=November 11, 2014|first1=Jacob|last1=Rossi|url-status=live|archive-url=https://web.archive.org/web/20150111145128/http://blogs.msdn.com/b/ie/archive/2014/11/11/living-on-the-edge-our-next-step-in-interoperability.aspx|archive-date=January 11, 2015|access-date=February 27, 2025}}{{cite web|url=https://www.theverge.com/2015/1/27/7925007/microsoft-project-spartan-browser-extensions|title=Microsoft reveals its Internet Explorer successor will support extensions|publisher=Vox Media|website=The Verge|date=January 27, 2015|first1=Tom|last1=Warren|url-status=live|archive-url=https://web.archive.org/web/20170708192517/https://www.theverge.com/2015/1/27/7925007/microsoft-project-spartan-browser-extensions|archive-date=July 8, 2017|df=mdy-all}}

Edge integrates with Microsoft's online platforms to provide voice control, search functionality, and dynamic information related to searches within the address bar. Users can make annotations to web pages that can be stored to and shared with OneDrive,{{cite web|url=https://www.theverge.com/2015/1/21/7863331/microsoft-project-spartan-new-web-browser|title=Microsoft officially announces Spartan, its new web browser for Windows 10|publisher=Vox Media|date=January 21, 2015|first1=Nathan|last1=Ingraham|website=The Verge|url-status=live|archive-url=https://web.archive.org/web/20150121193927/http://www.theverge.com/2015/1/21/7863331/microsoft-project-spartan-new-web-browser|archive-date=January 21, 2015|df=mdy-all}} and can save HTML and MHTML pages to their computers. It also integrates with the "Reading List" function and provides a "Reading Mode" that strips unnecessary formatting from pages to improve their legibility.

When preliminary support for browser extensions was added in March 2016 with build 14291, only three extensions were initially supported. Microsoft indicated that the delay in allowing extensions and the small number was due to security concerns.{{cite web|url=https://www.makeuseof.com/tag/everything-need-know-microsoft-edge-browser-extensions/|title=Everything You Need to Know About Microsoft Edge Browser Extensions|author=Tina Sieber|work=MakeUseOf|date=March 21, 2016|access-date=March 22, 2016|url-status=live|archive-url=https://web.archive.org/web/20160322013957/http://www.makeuseof.com/tag/everything-need-know-microsoft-edge-browser-extensions/|archive-date=March 22, 2016|df=mdy-all}}

Microsoft Edge Legacy release cadence was tied to the Windows release cycle and used the Windows Insider Program to preview new versions of the browser. These pre-release builds were known as "Edge Preview". Every major new release of Windows 10/10 Mobile included an updated version of Edge Legacy and its render engine until the release of New Edge.

File:Project Spartan logo.svg

In December 2014, writing for ZDNet, technology writer Mary Jo Foley reported that Microsoft was developing a new web browser codenamed "Spartan". She said that "Spartan" would be treated as a new product separate from Internet Explorer, with Internet Explorer 11 retained alongside it for compatibility.{{cite web|first1=Mary Jo|last1=Foley|author-link=Mary Jo Foley|url=https://www.zdnet.com/article/microsoft-is-building-a-new-browser-as-part-of-its-windows-10-push/|title=Microsoft is building a new browser as part of its Windows 10 push|publisher=CBS Interactive|website=ZDNet|date=December 29, 2014|url-status=live|archive-url=https://web.archive.org/web/20141230004609/http://www.zdnet.com/article/microsoft-is-building-a-new-browser-as-part-of-its-windows-10-push/|archive-date=December 30, 2014|df=mdy-all}}

In early January 2015, The Verge obtained further details surrounding "Spartan" from sources close to Microsoft, including reports that it would replace Internet Explorer on both the desktop and mobile versions of Windows.{{cite web|url=https://www.theverge.com/2015/1/8/7516489/windows-10-new-browser-spartan-features|title=Windows 10s new browser will have the most advanced features ever|publisher=Vox Media|date=January 8, 2015|website=The Verge|first1=Tom|last1=Warren|url-status=live|archive-url=https://web.archive.org/web/20170814061610/https://www.theverge.com/2015/1/8/7516489/windows-10-new-browser-spartan-features|archive-date=August 14, 2017|df=mdy-all}} Microsoft officially unveiled "Spartan" during a Windows-focused keynote on January 21, 2015. It was described as a separate product from Internet Explorer, although its final name was not announced.{{cite web|url=https://www.theverge.com/2015/3/17/8230631/microsoft-is-killing-off-the-internet-explorer-brand|title=Microsoft is killing off the Internet Explorer brand|website=The Verge|publisher=Vox Media|first1=Tom|last1=Warren|date=March 17, 2015|url-status=live|archive-url=https://web.archive.org/web/20150318040302/http://www.theverge.com/2015/3/17/8230631/microsoft-is-killing-off-the-internet-explorer-brand|archive-date=March 18, 2015|df=mdy-all}}

"Spartan" was first made publicly available as the default browser of Windows 10 Technical Preview build 10049, released on March 30, 2015.{{cite news|title=Project Spartan gets its first public outing in new Windows 10 build|url=https://arstechnica.com/information-technology/2015/03/project-spartan-gets-its-first-public-outing-in-new-windows-10-build/|website=Ars Technica|publisher=Condé Nast|access-date=March 30, 2015|date=March 30, 2015|url-status=live|archive-url=https://web.archive.org/web/20150331002854/http://arstechnica.com/information-technology/2015/03/project-spartan-gets-its-first-public-outing-in-new-windows-10-build/|archive-date=March 31, 2015|df=mdy-all}} The new engine used by "Spartan" was available in Windows 10 builds as part of Internet Explorer 11, Microsoft later announced that Internet Explorer would be deprecated on Windows and would not use the "Spartan" engine.{{cite web|url=https://www.cnet.com/how-to/how-to-enable-spartans-edge-rendering-engine-in-windows-10/|title=How to enable Spartan's Edge Rendering Engine in Windows 10|publisher=CBS Interactive|date=February 19, 2015|website=CNET|first1=Sarah|last1=Jacobsson Purewal|url-status=live|archive-url=https://web.archive.org/web/20150313223859/http://www.cnet.com/how-to/how-to-enable-spartans-edge-rendering-engine-in-windows-10/|archive-date=March 13, 2015|df=mdy-all}}

On April 29, 2015, during the Build Conference keynote, it was announced that "Spartan" would officially be known as Microsoft Edge.{{cite web|title=This is Microsoft Edge, the replacement for Internet Explorer|url=https://www.theverge.com/2015/4/29/8511169/microsoft-edge-official-name-internet-explorer-upgrade|website=The Verge|access-date=February 27, 2025|date=April 29, 2015|url-status=live|archive-url=https://web.archive.org/web/20150429211200/http://www.theverge.com/2015/4/29/8511169/microsoft-edge-official-name-internet-explorer-upgrade|archive-date=April 29, 2015}} The browser's logo and branding were designed to maintain continuity with the branding of Internet Explorer.{{cite news|url=http://www.neowin.net/news/microsoft-reveals-edges-new-logo|title=Microsoft reveals Edge's new logo|first=Brad|last=Sams|work=Neowin|publisher=Neowin, LLC|date=April 29, 2015|access-date=May 1, 2015|url-status=live|archive-url=https://web.archive.org/web/20150501002407/http://www.neowin.net/news/microsoft-reveals-edges-new-logo|archive-date=May 1, 2015|df=mdy-all}} The Project "Spartan" branding was used in versions released after Build 2015. On June 25, 2015, Microsoft released version 19.10149 for Windows 10 Mobile which included the new brand. Version 20.10158 followed on June 28, 2015, for the desktop versions, also including the updated branding. Then on July 15, 2015, Microsoft released version 20.10240 as the final release to Insiders. The same version was rolled out to consumers on July 29, 2015.

On August 12, 2015, Microsoft started the preview program for the next version of Microsoft Edge when they released version 20.10512 to Mobile users. Six days later, version 20.10525 followed for desktop users. These preview versions received multiple updates. On November 5, 2015, Microsoft released version 25.10586 as the final release for Edge's second public release for desktop users. The update was then rolled out to desktop and Xbox users (as part of the New Xbox Experience Update, which was also the initial release of Edge on that platform) on November 12, 2015. Then on November 18, 2015, the update was rolled out to Windows 10 Mobile, also as the initial (stable) release on that platform. Finally, on November 19, 2015, the update was also made available as part of the Windows Server 2016 Technical Preview 4.{{Cite journal|last=Foley|first=Mary Jo|date=2016-10-12|title=Microsoft's Windows Server 2016 hits general availability|url=https://www.zdnet.com/article/microsofts-windows-server-2016-hits-general-availability/|journal=ZDNet|archive-url=https://web.archive.org/web/20161015034432/https://www.zdnet.com/article/microsofts-windows-server-2016-hits-general-availability/|archive-date=15 October 2016|url-status=live}}

In April 2018, Edge added tab audio muting.{{Cite web|url=https://techcrunch.com/2018/04/27/microsofts-edge-browser-not-lets-you-mute-tabs/|title=Microsoft's Edge browser now lets you mute tabs|website=TechCrunch|date=April 27, 2018|language=en-US|access-date=2019-04-16|archive-date=May 27, 2022|archive-url=https://web.archive.org/web/20220527115027/https://techcrunch.com/2018/04/27/microsofts-edge-browser-not-lets-you-mute-tabs/|url-status=live}} In June 2018, support for the Web Authentication specifications were added to Windows Insider builds, with support for Windows Hello and external security tokens.{{cite web|url=https://blogs.windows.com/windowsexperience/2018/05/31/announcing-windows-10-insider-preview-build-17682/#oHYCS0GkF95OMzKH.97|title=Announcing Windows 10 Insider Preview Build 17682|author=Sarkar|display-authors=etal|publisher=Microsoft|date=2018-05-23|access-date=2018-06-25|archive-date=April 7, 2019|archive-url=https://web.archive.org/web/20190407194514/https://blogs.windows.com/windowsexperience/2018/05/31/announcing-windows-10-insider-preview-build-17682/#oHYCS0GkF95OMzKH.97|url-status=live}}{{Cite web|url=https://www.engadget.com/2018-07-31-microsoft-edge-now-supports-passwordless-sign-ins.html|title=Microsoft Edge now supports passwordless sign-ins|website=Engadget|date=July 31, 2018|language=en|access-date=2025-02-27|archive-date=October 5, 2018|archive-url=https://web.archive.org/web/20181005030804/https://www.engadget.com/2018/07/31/microsoft-edge-now-supports-passwordless-sign-ins/|url-status=live}}

August 2019 saw the removal of Edge support for the EPUB file format.{{Cite web|url=https://www.windowscentral.com/microsoft-edge-will-no-longer-support-epub-file-format-e-books|title=Microsoft Edge will no longer support ePub file format for e-books|date=2019-08-23|website=Windows Central|language=en|access-date=2019-11-22|archive-date=August 3, 2020|archive-url=https://web.archive.org/web/20200803230127/https://www.windowscentral.com/microsoft-edge-will-no-longer-support-epub-file-format-e-books|url-status=live}}

Microsoft stopped supporting Edge Legacy (for desktop) on March 9, 2021. On April 13, 2021, Microsoft released a cumulative monthly security update which completely removed Edge Legacy and replaced it with the new Chromium-based Edge, if not already present.{{Cite web|title=Microsoft will uninstall its old Edge browser from Windows PCs on April 13th|url=https://www.engadget.com/microsoft-edge-legacy-phase-out-232116614.html|access-date=2021-02-06|website=Engadget|date=February 5, 2021|language=en-US|archive-date=February 6, 2021|archive-url=https://web.archive.org/web/20210206164717/https://www.engadget.com/microsoft-edge-legacy-phase-out-232116614.html|url-status=live}} While the initial release of New Edge on Xbox, as bundled with the September 2021 update, replaced Edge Legacy and marked the end of Xbox System Software support for it.

{{Main|EdgeHTML}}

EdgeHTML is the proprietary browser engine developed for Edge [Legacy]. It is a fork of MSHTML (Trident) with all legacy code of older versions of Internet Explorer removed, with the majority of its source code rewritten to support web standards and interoperability with other modern browsers.{{cite web|url=https://www.neowin.net/news/whats-powering-spartan-internet-explorer-of-course|title=What's powering Spartan? Internet Explorer, of course|work=Neowin|url-status=live|archive-url=https://web.archive.org/web/20151216181932/http://www.neowin.net/news/whats-powering-spartan-internet-explorer-of-course|archive-date=2015-12-16}}{{cite web|url=https://www.zdnet.com/article/microsofts-spartan-browser-whats-under-the-hood/|title=Microsoft's Spartan browser: What's under the hood|publisher=CBS Interactive|date=2015-01-22|website=ZDNet|first1=Mary Jo|last1=Foley|author-link=Mary Jo Foley|url-status=live|archive-url=https://web.archive.org/web/20160306112840/http://www.zdnet.com/article/microsofts-spartan-browser-whats-under-the-hood/|archive-date=2016-03-06}} EdgeHTML is written in C++.{{cite web|url=https://learn.microsoft.com/en-us/archive/blogs/ie/internet-explorer-8-and-acid2-a-milestone|title=Internet Explorer 8 and Acid2: A Milestone|publisher=IEBlog|first=Dean|last=Hachamovitch|date=2007-12-19|url-status=live|archive-url=https://web.archive.org/web/20110827092952/http://blogs.msdn.com/b/ie/archive/2007/12/19/internet-explorer-8-and-acid2-a-milestone.aspx|archive-date=2011-08-27}}

The rendering engine was first released as an experimental option in Internet Explorer 11 as part of the Windows 10 Preview 9926 build.{{cite web|last=Rubino|first=Daniel|url=https://www.windowscentral.com/enable-spartan-rendering-engine-ie11|title=Here's how to enable the Spartan Edge rendering engine for IE11 in Windows 10|website=Windows Central|date=2015-01-25|access-date=2015-01-29|url-status=live|archive-url=https://web.archive.org/web/20150127223849/http://www.windowscentral.com/enable-spartan-rendering-engine-ie11|archive-date=2015-01-27}}

EdgeHTML is meant to be fully compatible with the WebKit layout engine used by Safari and other browsers. Microsoft stated their original acceptance criteria: "Any Edge–WebKit differences are bugs that we're interested in fixing."{{cite web|url=https://blogs.windows.com/msedgedev/2015/06/17/building-a-more-interoperable-web-with-microsoft-edge/|title=Building a more interoperable Web with Microsoft Edge|website=Blogs.windows.com|access-date=2017-04-27|date=2015-06-17|url-status=live|archive-url=https://web.archive.org/web/20170630154530/https://blogs.windows.com/msedgedev/2015/06/17/building-a-more-interoperable-web-with-microsoft-edge/|archive-date=2017-06-30}}

A review of the engine in the beta Windows 10 build by AnandTech found substantial benchmark improvements over MSHTML (Trident), particularly its new Chakra JavaScript engine performance, which had come up to par with that of Google Chrome.{{cite web|url=https://www.anandtech.com/show/8932/internet-explorer-project-spartan-shows-large-performance-gains|title=Internet Explorer Project Spartan Shows Large Performance Gains|date=2015-01-25|author=Brett Howse|website=AnandTech|url-status=live|archive-url=https://web.archive.org/web/20151208111251/http://www.anandtech.com/show/8932/internet-explorer-project-spartan-shows-large-performance-gains|archive-date=2015-12-08}} Other benchmarks focusing on the performance of the WebGL API found EdgeHTML to perform much better than Google Chrome and Mozilla Firefox.{{cite web|title=Benchmark Deep-Dive: Microsoft Windows 10 Spartan Browser vs. IE11 vs. Google Chrome 41 vs. Mozilla Firefox|url=https://www.winbuzzer.com/benchmark-deep-dive-microsoft-windows-10-spartan-browser-vs-ie11-vs-google-chrome-41-vs-mozilla-firefox-36/|website=WinBuzzer|date=February 9, 2015|access-date=2015-02-09|url-status=live|archive-url=https://web.archive.org/web/20150210132612/http://www.winbuzzer.com/benchmark-deep-dive-microsoft-windows-10-spartan-browser-vs-ie11-vs-google-chrome-41-vs-mozilla-firefox-36/|archive-date=2015-02-10}}

{{More citations needed section|date=April 2025}}

{{Incomplete list|date=April 2025}}

Early benchmarks of the EdgeHTML engine—included in the first beta release of Edge in Windows 10 Build 10049—had drastically better JavaScript performance due to the new Chakra JavaScript engine being used instead of the older Chakra JScript engine in Internet Explorer 11, with similar performance to Google Chrome 41 and Mozilla Firefox 37.{{cite web|url=http://windowsable.com/best-web-browsers-for-windows-10/|title=Best Web Browsers For Windows 10|date=December 22, 2015|url-status=deviated|archive-url=https://web.archive.org/web/20160501010915/http://windowsable.com/best-web-browsers-for-windows-10/|archive-date=May 1, 2016|df=mdy-all}} In the SunSpider benchmark, Edge performed faster than other browsers,{{cite web|url=https://www.anandtech.com/show/8932/internet-explorer-project-spartan-shows-large-performance-gains|title=Internet Explorer Project Spartan Shows Large Performance Gains|publisher=Purch|date=January 25, 2015|website=AnandTech|first1=Brett|last1=Howse|url-status=live|archive-url=https://web.archive.org/web/20151208111251/http://www.anandtech.com/show/8932/internet-explorer-project-spartan-shows-large-performance-gains|archive-date=December 8, 2015|df=mdy-all}} while in other benchmarks it operated slower than Google Chrome, Mozilla Firefox and Opera.{{cite web|url=http://www.tekrevue.com/spartan-benchmarks-ie-chrome-firefox-opera|title=Windows 10 Browser Benchmarks: Spartan vs. IE, Chrome, Firefox, and Opera|date=April 1, 2015|url-status=dead|archive-url =https://web.archive.org/web/20151226174659/http://www.tekrevue.com/spartan-benchmarks-ie-chrome-firefox-opera|archive-date=December 26, 2015|df=mdy-all}}

Later benchmarks conducted with the version included in 10122 showed significant performance improvement compared to both IE11 and Edge back in 10049. According to Microsoft's benchmark result, this iteration of Edge performed better than both Chrome and Firefox in Google's Octane 2.0 and Apple's Jetstream benchmark.{{cite web|url=https://blogs.windows.com/msedgedev/2015/05/20/delivering-fast-javascript-performance-in-microsoft-edge|title=Delivering fast JavaScript performance in Microsoft Edge|date=May 20, 2015|url-status=live|archive-url =https://web.archive.org/web/20151103062842/http://blogs.windows.com/msedgedev/2015/05/20/delivering-fast-javascript-performance-in-microsoft-edge|archive-date=November 3, 2015|website=Windows Blogs|publisher=Microsoft|df=mdy-all}}

Edge originally lacked support for open media standards such as WebM and Opus, but these were later added in Edge 14.14291.{{cite web|date=April 18, 2016|title=WebM, VP9 and Opus Support in Microsoft Edge|url=https://blogs.windows.com/msedgedev/2016/04/18/webm-vp9-and-opus-support-in-microsoft-edge|url-status=live|archive-url=https://web.archive.org/web/20161021034013/https://blogs.windows.com/msedgedev/2016/04/18/webm-vp9-and-opus-support-in-microsoft-edge/|archive-date=October 21, 2016|access-date=September 18, 2016|website=Windows Blogs|publisher=Microsoft|df=mdy-all}}

In July 2015, Edge scored 377 out of 555 points on the HTML5test. Chrome 44 and Firefox 42 scored 479 and 434 respectively, while Internet Explorer 11 scored 312.{{cite web|url=https://thenextweb.com/news/is-it-time-to-love-microsoft-again|title=Microsoft is trying to win back Web developers with its Edge browser|author=Owen Williams|date=July 29, 2015|work=TNW|access-date=February 23, 2025|url-status=live|archive-url=https://web.archive.org/web/20150730041320/http://thenextweb.com/microsoft/2015/07/29/is-it-time-to-love-microsoft-again/|archive-date=July 30, 2015|df=mdy-all}}

In August 2015, Microsoft released Windows 10 Build 10532 to insiders, which included Edge 21.10532.0. This beta version scored 445 out of 555 points on the HTML5test.{{cite web|title=Edge HTML5 improvements teased for upcoming Windows 10 Insider build|url=https://www.neowin.net/news/edge-html5-improvements-teased-for-upcoming-windows-10-insider-build/|website=Neowin|access-date=February 23, 2025|url-status=live|archive-url=https://web.archive.org/web/20150905064754/http://www.neowin.net/news/edge-html5-improvements-teased-for-upcoming-windows-10-insider-build|archive-date=September 5, 2015|df=mdy-all}}

In July 2016, with the release of Windows 10 Build 14390 to insiders, the HTML5 test score of the browser's development version was 460 out of 555 points. Chrome 51 scored 497, Firefox 47 scored 456, and Safari 9.1 scored 370.{{Cite web |title=HTML5test - How well does your browser support HTML5? |url=https://html5test.co/results/desktop.html |access-date=2024-06-10 |website=html5test.co}}

In June 2017, Edge 17 had scored 492/555 on HTML5test.{{Cite web |title=HTML5test - Edge & Internet Explorer |url=https://html5test.com/results/desktop/timeline/edge.html |archive-url=https://web.archive.org/web/20200701004143/http://html5test.com/results/desktop/timeline/edge.html |archive-date=July 1, 2020 |url-status=dead |access-date=February 21, 2025}}

In June 2016, Microsoft published benchmark results to prove the superior power efficiency of Edge in comparison to all other major web browsers.{{Cite web|url=https://winbuzzer.com/2016/07/14/microsoft-tests-show-edge-browser-best-battery-life-video-playback-xcxwbn/|title=Microsoft Details Edge Browser Benchmark Results to Prove Its Supremacy|last=Kasanmascheff|first=Markus|date=July 14, 2016|website=WinBuzzer|access-date=February 23, 2025|url-status=live|archive-url=https://web.archive.org/web/20180205151138/https://winbuzzer.com/2016/07/14/microsoft-tests-show-edge-browser-best-battery-life-video-playback-xcxwbn/|archive-date=February 5, 2018|df=mdy-all}} Opera questioned the accuracy and provided their own test results where Opera came out on top.{{Cite web|url=https://blogs.opera.com/desktop/2016/06/over-the-edge/|title=Over the edge?|date=June 22, 2016|website=Opera blogs|language=en-US|access-date=February 23, 2025|url-status=live|archive-url=https://web.archive.org/web/20170205190345/http://www.opera.com/blogs/desktop/2016/06/over-the-edge/|archive-date=February 5, 2017|df=mdy-all}} Independent testing by PC World confirmed Microsoft's results.{{Cite web|url=https://www.pcworld.com/article/415351/which-browser-is-best-on-battery-we-test-edge-vs-chrome-vs-opera-vs-firefox.html|title=Which browser is best for battery life: We test Edge vs. Chrome vs. Opera vs. Firefox|date=June 27, 2016|access-date=February 23, 2025|url-status=live|archive-url=https://web.archive.org/web/20160715025748/http://www.pcworld.com/article/3087338/browsers/which-browser-is-best-on-battery-we-test-edge-vs-chrome-vs-opera-vs-firefox.html|archive-date=July 15, 2016|df=mdy-all}} However, tests conducted by Linus Sebastian in June 2017 instead showed that, at that time, Chrome had the best battery performance.{{cite web|url=https://betanews.com/2017/06/26/google-chrome-microsoft-edge-battery-life-tests/|title=Google Chrome bests Microsoft Edge in new battery life tests|website=betanews.com|date=June 26, 2017|access-date=October 7, 2017|url-status=live|archive-url=https://web.archive.org/web/20171007070245/https://betanews.com/2017/06/26/google-chrome-microsoft-edge-battery-life-tests/|archive-date=October 7, 2017|df=mdy-all}}

In an August 2015 review of Windows 10 by Dan Grabham of TechRadar, Microsoft Edge was praised for its performance, despite not being in a feature-complete state at launch.{{cite web|url=http://www.techradar.com/reviews/pc-mac/software/operating-systems/windows-10-1267364/review/|title=Windows 10 Review|work=TechRadar|publisher=Future plc|access-date=July 30, 2015|url-status=live|archive-url=https://web.archive.org/web/20150729004659/http://www.techradar.com/reviews/pc-mac/software/operating-systems/windows-10-1267364/review|archive-date=July 29, 2015}} Andrew Cunningham of Ars Technica praised the browser for being "tremendously promising" and "a much better browser than Internet Explorer ever was" but criticized it for its lack of functionality on launch.{{cite web|title=Review: Windows 10 is the best version yet—once the bugs get fixed|url=https://arstechnica.com/gadgets/2015/07/review-windows-10-is-the-best-version-yet-once-the-bugs-get-fixed/|website=Ars Technica|date=July 29, 2015|access-date=July 31, 2015|url-status=live|archive-url=https://web.archive.org/web/20150730231454/http://arstechnica.com/gadgets/2015/07/review-windows-10-is-the-best-version-yet-once-the-bugs-get-fixed/|archive-date=July 30, 2015}} Thom Holwerda of OSNews criticized Edge in August 2015 for its hidden URL bar, lack of user-friendliness, poor design and a tab system that is "so utterly broken it should never have shipped in a final release". He described the browser's implemented features as "some sort of cosmic joke", saying that "infuriating doesn't even begin to describe it".{{cite web|url=http://www.osnews.com/story/28809/Windows_it_s_always_the_next_version|title=Windows: it's always the next version|work=OSNews|access-date=September 3, 2015|url-status=live|archive-url=https://web.archive.org/web/20150905054301/http://www.osnews.com/story/28809/Windows_it_s_always_the_next_version|archive-date=September 5, 2015}}

Data from August 2015, a few weeks after release, showed that user uptake of Edge was low, with only 2% of overall computer users using the new browser. Among Windows 10 users, usage peaked at 20% and then dropped to 14% through August 2015.{{cite web|url=http://www.businessinsider.com/microsoft-edge-marketshare-2015-9|title=Barely anybody is using Microsoft's new browser|author=Max Slater-Robins|date=September 2, 2015|work=Business Insider|access-date=September 3, 2015|quote=shows that Edge peaked at approximately 20% usage among Windows 10 users at the end of July, before dropping down to 14% by the end of August|url-status=live|archive-url=https://web.archive.org/web/20150905004020/http://www.businessinsider.com/microsoft-edge-marketshare-2015-9|archive-date=September 5, 2015}}

In October 2015, a security researcher published a report outlining a bug in Edge's "InPrivate" mode, causing data related to visited sites to still be cached in the user's profile directory, theoretically making it possible for others to determine sites visited. The bug gained mainstream attention in early February 2016,{{cite web|title=Microsoft Edge InPrivate browsing mode is full of fail and not private|url=https://www.csoonline.com/article/554523/microsoft-edge-inprivate-browsing-mode-is-full-of-fail-and-not-private.html|website=CSO Online|date=February 1, 2016|publisher=IDG Communications, Inc.|access-date=February 27, 2025|url-status=live|archive-url=https://web.archive.org/web/20160201225559/http://www.networkworld.com/article/3028084/security/microsoft-edge-inprivate-browsing-mode-is-full-of-fail-and-not-private.html|archive-date=February 1, 2016}} and was fixed with a cumulative update on February 9, 2016.{{cite web|url=http://windows.microsoft.com/windows-10/update-history-windows-10|title=KB3135173, OS build 10596.104|publisher=Microsoft|date=February 8, 2016|access-date=February 27, 2025|url-status=deviated|archive-url=https://web.archive.org/web/20160305002110/http://windows.microsoft.com/en-us/windows-10/update-history-windows-10|archive-date=March 5, 2016}}

According to StatCounter, in August 2019, Edge overtook the market share of Internet Explorer (IE) on PCs, ranking third place at 9.14%{{Cite web|title=Desktop Browser Market Share Worldwide: 19 Oct - 17 Nov 2021|url=https://gs.statcounter.com/browser-market-share/desktop/worldwide/#daily-20211019-20211117|access-date=2021-11-19|website=StatCounter Global Stats|language=en|archive-date=October 11, 2017|archive-url=https://web.archive.org/web/20171011022101/https://gs.statcounter.com/browser-market-share/desktop/worldwide#daily-20211019-20211117|url-status=live}} and IE in sixth. On Xbox, Edge replaced IE as the dominant browser shortly after its release in November 2015.{{Cite web|url=https://gs.statcounter.com/browser-market-share/console/worldwide/#monthly-201501-201801|title=Console Browser Market Share Worldwide: Jan 2015 - Jan 2018|website=StatCounter Global Stats|language=en|access-date=2019-09-21|archive-date=September 21, 2019|archive-url=https://web.archive.org/web/20190921163818/https://gs.statcounter.com/browser-market-share/console/worldwide#monthly-201501-201801|url-status=live}}

{{reflist}}

• {{Cite web|url=https://blogs.windows.com/msedgedev/2015/01/22/project-spartan-and-the-windows-10-january-preview-build/|title=Project Spartan and the Windows 10 January Preview Build|work=Windows Blogs|publisher=Microsoft|date=January 22, 2015|first=Jason|last=Weber|access-date=January 23, 2025|archive-date=January 22, 2015|archive-url=https://web.archive.org/web/20150122190033/http://blogs.msdn.com/b/ie/archive/2015/01/22/project-spartan-and-the-windows-10-january-preview-build.aspx|url-status=live}}

{{Timeline of web browsers|the 2010s}}

{{Web browsers|discontinued}}

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Edge Legacy

Category:Discontinued web browsers

Category:Discontinued Windows components

Category:2015 software

Category:Microsoft Edge