Firefox 27 was released today and we added it to our browser testing cloud. You can start testing your code and sites in this new browser release right now.

Web browser testing in Firefox 27

Try Mozilla Firefox 27 in Browserling now!

Mozilla Firefox 27 News

  • You can now run more than one service at a time with Firefox SocialAPI, allowing you to receive notifications, chat and more from multiple integrated services.
  • TLS 1.1 (RFC 4346) and TLS 1.2 (RFC 5246) is now enabled by default.
  • Azure/Skia content rendering is now working on Linux.
  • Support for SPDY 3.1 protocol has been added.
  • Canvas now supports dashed line.

Mozilla Firefox 27 Webdev News

  • Ability to reset style sheets using 'all:unset'
  • You can now choose to deobfuscate javascript in the debugger (see 762761)
  • Added support for scrolled fieldsets.
  • Implemented allow-popups directive for iframe sandbox, enabling increased security.
  • CSS cursor keywords -moz-grab and -moz-grabbing have been unprefixed.
  • Added support for ES6 generators in SpiderMonkey.
  • Implemented support for mathematical function Math.hypot() in ES6.
  • Breakpoints can now be set on DOM events.
  • JavaScript in the debugger panel can be unminified, using the { } button.
  • The inspector now has an "edit-element-html" feature, without needing an add-on.
  • Background-URLs and colors have preview in inspector. Even hovering over canvas elements will give a pop-up with an image preview.
  • Reflow logging has been added.
  • Styles of SVG elements are now inspectable.
  • Failure to find the image when clicking URL link in CSS inspector has been fixed.
  • The -moz-grab and -moz-grabbing keywords on the CSS cursor property have been unprefixed to grab and grabbing.
  • The "true" value for text-align has been added.
  • The all shorthand property has been added.
  • The unset global value has been added; it allows to reset any CSS property.
  • The color value of the <input> type attribute has been implemented on desktop platforms. It was already available on mobile ones.
  • The spread operator is now supported in Function calls.
  • The mathematical function Math.hypot() has been implemented.
  • The yield* expression is now implemented.
  • The MapIterator, SetIterator and ArrayIterator objects now match the specification.
  • Loops of form for..of now expect the ES2015 standard iterator protocol moving away from SpiderMonkey old iterator protocol using StopIteration.
  • String.match and String.replace now reset RegExp.lastIndex.
  • Support for the two setRange() methods on the HTMLInputElement interface has been added.
  • Event.isTrusted() is now unforgeable.
  • Blending of SVG elements using the mix-blend-mode property has been implemented.

Mozilla Firefox 27 Security News

  • Inconsistent JavaScript handling of access to Window objects.
  • NSS ticket handling issues.
  • Crash when using web workers with asm.js.
  • Firefox default start page UI content invokable by script.
  • Cross-origin information leak through web workers.
  • Use-after-free with imgRequestProxy and image proccessing.
  • XSLT stylesheets treated as styles in Content Security Policy.
  • Profile path leaks to Android system log.
  • Information disclosure with *FromPoint on iframes.
  • Incorrect use of discarded images by RasterImage.
  • UI selection timeout missing on download prompts.
  • Clone protected content with XBL scopes.
  • Miscellaneous memory safety hazards.

Mozilla Firefox 27 Issues

  • crash in gfxContext::PushClipsToDT with Direct2D 1.1 (d3d11.dll 6.2 or 6.3).
  • Text rendering issues on Windows 7 with Platform Update KB2670838 (MSIE 10 Prerequisite).

Happy cross-browser testing in Firefox 27!