New Developer Features in EdgeHTML 13

Microsoft’s big November Windows 10 update carried with it some significant improvements not only in the OS but also in the Edge browser and the components it exposes to developers.  EdgeHTML, the core rendering engine got updates including better HTML5 Support while Chakra, the Javascript execution engine got improved ES7/ES2016 support including async functions.

EdgeHTML has added support for more CSS and HTML5 elements boosting it’s HTML5Test score from 402 to 458, a vast improvement that puts it on par with FireFox’s 467 but still falling far behind Chrome’s 521.  This table from the Microsoft Edge Dev Blog shows the major features added in EdgeHTML 13.

CSS

• CSS Mutability Pseudo-classes
  • :read-write
  • :read-only
• CSS Range Pseudo-classes
  • :in-range
  • :out-of-range
• CSS initial keyword
• CSS unset keyword

File APIs

• a[download] attribute

User Input

• input type=text selectionDirection
• input type=time
• input type=datetime-local
• <meter> element
• oninvalid event handler for the element document and window
• Pointer Lock (Mouse Lock)

Graphics

• Canvas ellipse
• Canvas blending modes
• Extended srcset and sizes (see the associated blog post and demo)
• <picture> element (see the associated blog post and demo)
• SVG external content

Communication

• Object RTC (see the associated blog post and demos)

Tools

• Restored support for docking the F12 Developer Tools

Web Components

• <template> element (see our blog post on this and other Web Components technologies)

While EdgeHTML 13 may be playing catch up with other browsers, the Chakra JavaScript execution engine is leaving them in it’s virtual dust.  The latest version of Chakra includes asm.js support by default as well as performance enhancements that put it 10% higher in support for ES6 features than FireFox and nearly 20% higher than Chrome.

This list also from the Microsoft Edge Dev Blog shows the features added in the latest version.

• ES2016 Async Functions (behind “Enable experimental JavaScript features” flag)
• ES2016 Exponentiation operator (behind “Enable experimental JavaScript features” flag)
• asm.js is now enabled by default (previously behind a flag); see our blog post and demo
• ES2015 Classes now enabled by default (previously behind a flag)
• ES2015 Destructuring now available behind the Experimental JavaScript features flag

For more information about the improvements in Microsoft’s newest browser, check out the blog post at Microsoft Edge Dev Blog.