EdgeHTML


EdgeHTML is a proprietary browser engine from Microsoft, originally used in the Edge web browser. In 2018, Microsoft announced plans to rebuild Edge as a Chromium-based browser, using the Blink engine; this new Edge was released on January 15, 2020. However, a Microsoft project manager has also stated that EdgeHTML will continue to be maintained for Universal Windows Platform apps.

Usage in Windows

EdgeHTML is a fork of Microsoft's Trident that was the engine of the Internet Explorer browser. It was first released as an experimental option in Internet Explorer 11 as part of the Windows 10 Technical Preview build 9879.
EdgeHTML is designed as a software component to allow software developers to easily add web browsing functionality to their own applications. It presents a COM interface for accessing and editing web pages in any COM-supported environment, like C++ and.NET. For instance, a web browser control can be added to a C++ program and EdgeHTML can then be used to access the page currently displayed in the web browser and retrieve element values. Events from the web browser control can also be captured. It is also used to render WinRT-apps that are based on web technologies.

Release history

EdgeHTMLEdgeRelease dateNotes
12.0November 12, 2014Initial version of EdgeHTML to be included as an experimental feature to Internet Explorer 11 to replace Trident 7.0 in next Project Spartan web browser, later renamed Microsoft Edge.
12.100490.10.10049March 31, 2015Introduced new features and came with the first version of Microsoft Edge.
12.1016620.10166July 9, 2015
  • localhost loopback became enabled by default. localhost could be toggled by navigating to about:flags.
  • Improved support for about:flags in locales other than en-US
  • Bug fixes
12.1024020.10240July 15, 2015Initial public release. Contains improvements to performance, support for HTML5 and CSS3.
12.1052520.10525August 18, 2015This release contains initial groundwork for Object RTC in Microsoft Edge.
12.1053220.10532August 27, 2015New features such as Pointer Lock, Canvas blending modes, and new input types.
13.1054721.10547September 18, 2015Edge HTML has been updated to version 13, extended support for HTML5 and CSS3, Extended srcset, a attribute, Canvas ellipse, SVG external content, WebRTC - Object RTC API.
13.1056523.10565October 12, 2015CSS initial and unset values, initial support for docked F12 Developer Tools.
13.1058625.10586November 5, 2015First public platform update, includes further enhancements to HTML5, including Object RTC support.
13.1109927.11099January 13, 2016Initial foundational work for EdgeHTML 14.
14.1426731.14267February 18, 2016Edge HTML has been updated to version 14, with initial plumbing for Web Notifications support.
14.1427931.14279March 4, 2016New experimental JavaScript feature support.
14.1429134.14291March 17, 2016Preview support for the VP9 video format on some devices.
14.1431637.14316April 6, 2016New F12 Developer Tools, New JavaScript features and experimental features and new Web Platform features.
14.1432737.14327April 20, 2016Beacon interface and accessibility improvements.
14.1434238.14342May 10, 2016Web Notifications, Beacon and Fetch APIs became enabled by default, Performance improvements for several common JavaScript APIs.
14.1435238.14352May 26, 2016H.264/AVC decoding became available through the ORTC API.
14.1435638.14356June 1, 2016Various performance and reliability improvements and bug fixes.
14.1436138.14361June 8, 2016TCP Fast Open is now disabled by default.
14.1436638.14366June 14, 2016Fixed an issue that could result in abnormally high CPU usage when open to a page with many animated GIFs, as well as an issue resulting in certain captchas not displaying correctly.
14.1436738.14367June 16, 2016Improvements to reduce battery usage on Windows 10 Mobile when Microsoft Edge is running in the background.
14.1437638.14376June 28, 2016Bug fixes and performance improvements.
14.1439338.14393August 2, 2016This is the stable channel release of EdgeHTML 14 with the Windows 10 Anniversary Update.
14.1490139.14901August 11, 2016This release adds about:flags settings for several features in development, including support for WebRTC 1.0 and Service Worker features.
14.1491539.1491539.14915Partial implementation of Webkit-Text-Stroke and CSS outline-offset, partial support for WebRTC 1.0.
14.1492639.14926September 14, 2016
  • Improved performance on websites with changes to large numbers of HTML Elements containing text by improving spellchecker efficiency. This results in substantially improved performance on websites like TweetDeck.
  • Addressed the largest cause of reliability issues in Insider builds of Microsoft Edge, which should improve reliability on major sites such as Facebook and Outlook.
    • 15.1494239.14942October 7, 2016EdgeHTML has been updated to version 15 with the following features :
    • Enabled H.264/AVC support by default for RTC scenarios
    • Improved ES6 Modules debugging experience in F12 Developer Tools
    • Various webpage performance improvements
    • Refactoring network logic in terms of Fetch algorithms in preparation for Service Worker Fetch interception
    • Ongoing work to add support for CSS Custom Properties
    • Ongoing work to add support for CSP 2.0, WebRTC 1.0 and Service Worker
    15.1495939.14959November 3, 2016Bug fixes and reliability improvements.
    15.1498639.14986December 7, 2016Multiple new platform features and developer tools.
    15.1506340.15063April 11, 2017This is the stable channel release of EdgeHTML 15 with the Windows 10 Creators Update.
    16.1629941.16299September 26, 2017This is the stable channel release of EdgeHTML 16 part of the 2017 Fall Creators Update.
  • WebAssembly enabled by default.
    • 17.1713442.17134April 30, 2018This is the stable channel release of EdgeHTML 17 with the Windows 10 April 2018 Update.
  • Support for Progressive Web Apps
  • CSS transforms on SVG elements
  • Support for Notification API
    • 18.1776344.17763October 2, 2018This is the stable channel release of EdgeHTML 18 with the Windows 10 October 2018 Update.
  • Support for Autoplay Policies
  • CSS Masking, overflow-wrap and overscroll-behavior support
  • Improvements to Developer Tools

    • EdgeHTML 12

    Microsoft first introduced the EdgeHTML rendering engine as part of Internet Explorer 11 in the Windows Technical Preview build 9879 on November 12, 2014. Microsoft planned to use EdgeHTML both in Internet Explorer and Project Spartan; in Internet Explorer it would exist alongside the Trident 7 engine from Internet Explorer 11, the latter being used for compatibility purposes. However, Microsoft decided to ship Internet Explorer 11 in Windows 10 as it was in Windows 8.1, leaving EdgeHTML only for the new Edge browser. EdgeHTML was also added to Windows 10 Mobile and the second Windows Server 2016 Technical Preview. It was officially released on July 29, 2015 as part of Windows 10.
    Unlike Trident, EdgeHTML does not support ActiveX. It also drops support for the X-UA-Compatible header, used by Trident to determine in which version it had to render a certain page. Microsoft also dropped the usage of Compatibility View-lists. Edge will recognize if a page requires any of the removed technologies to run properly and suggest to the user to open the page in Internet Explorer instead. Another change was spoofing the user agent string, which claims to be Chrome and Safari, while also mentioning KHTML and Gecko, so that web servers that use user agent sniffing send Edge users the full versions of web pages instead of reduced-functionality pages.
    EdgeHTML also made significant performance improvements over Trident, resulting in better JavaScript benchmark scores.
    Microsoft EdgeHTML 12Mozilla/5.0 AppleWebKit/537.36 Chrome/42.0.2311.135 Safari/537.36 Edge/12.10240
    Internet Explorer 11Mozilla/5.0 like Gecko

    Breaking from Trident, the new EdgeHTML engine will be focused on modern web standards and interoperability, rather than compatibility. The initial release of Edge HTML on Windows 10 included more than 4000 interoperability fixes.

    EdgeHTML 13

    On August 18, 2015, Microsoft released the first preview to EdgeHTML platform version 13 as part of Windows 10.0.10525, though it was still labeled as version 12. In subsequent updates, the support for HTML5 and CSS3 was extended to include new elements. Microsoft also included support for Object RTC and enabled ASM.js by default after it was added in version 12. The update's main focus was on improving the support for ECMAScript 6 and also including some features from ECMAScript 7. With that update to Chakra Edge provided to most extensive support for ECMAScript 6 according to the Kangax benchmark with 84%, 13% ahead of Mozilla Firefox 42, the then-current version of Firefox and runner-up.
    EdgeHTML 13.10586 was released in multiple versions of Windows. On November 12, 2015, the New Xbox One Experience-update for the Xbox One included EdgeHTML 13.10586, replacing Internet Explorer 10 in the process. It was released to Windows 10 as part of the November Update on the same day. On November 18, 2015, the updated got rolled out to Windows 10 Mobile users in the Insider Preview. Finally, Microsoft rolled out the same update to Windows Server 2016 as part of Technical Preview 4.

    EdgeHTML 14

    On December 16, 2015, Microsoft released the first build of Redstone. In January and February 2016, 4 other builds followed, all laying the foundational work for EdgeHTML 14. On February 18, 2016, Microsoft released the first version of EdgeHTML 14 as version 14.14267. This version of the engine contained almost no changes in standards support yet, but contained fundamental work for Web Notifications, WebRTC 1.0, improved ECMAScript and CSS support and also contained a number of new flags. Further, Microsoft announced that it is working on VP9, WOFF 2.0, Web Speech API, WebM, FIDO 2.0, Beacon and many other technologies.
    On August 2, 2016, EdgeHTML 14 was released to Windows 10 as part of the 2016 Anniversary Update.

    EdgeHTML 15

    On April 11, 2017, EdgeHTML 15 was released to Windows 10 as part of the 2017 Creators Update.

    EdgeHTML 16

    On October 8, 2017, EdgeHTML 16 was released to Windows 10 as part of the 2017 Fall Creators Update, having WebAssembly enabled by default.

    EdgeHTML 17

    On April 30, 2018, EdgeHTML 17 was released to Windows 10 as part of the 2018 April Update, with features such as Muting tabs with a click, Automatic filling of forms and credit card details, better reading with annotations, grammar tools, and more.

    EdgeHTML 18

    On October 2, 2018, EdgeHTML 18 was released to Windows 10 as part of the 2018 October Update, with features such as Autoplay Policies, CSS improvements, and improvements to the JavaScript engine, Chakra.

    Performance

    A review in 2015 of the engine in the latest Windows 10 build by AnandTech found substantial benchmark improvements over Trident, particularly JavaScript engine performance, which is now up to par with that of Google Chrome. Other benchmarks focusing on the performance of the WebGL API found EdgeHTML to perform much better than Google Chrome and Mozilla Firefox.

    Compatibility

    EdgeHTML's rendering is meant to be fully compatible with the rendering of the Blink and WebKit layout engines, used by Google Chrome and Safari, respectively. Microsoft has stated that "any Edge-WebKit differences are bugs that we’re interested in fixing."

    Miscellaneous

    As of 2018, EdgeHTML is historically one of the few browsing engines to support smooth transitioning of CSS linear gradients.