Firefox 47 is now available for cross-browser testing. Version 47 was released today by Mozilla. We just finished installing it on our browser testing cloud and it's available to everyone!

Cross-browser testing in Firefox 47

Try Firefox 47 in Browserling now!

Firefox 47 adds Google's Widevine CDM on Windows and Mac OS X so streaming services like Amazon Video can switch from Silverlight to encrypted HTML5 video. Enables VP9 video codec for users with fast machines. Adds the ability of embedded YouTube videos to play with HTML5 video if Flash is not installed. Adds the Latgalian language. Firefox 47 is the last Firefox version to support Mac OS X Snow Leopard, Mac OS X Lion, OS X Mountain Lion, and Android 2.3.x.

What's new in Firefox 47?

  • Enable VP9 video codec for users with fast machines.
  • Latgalu [ltg] locale added. Wikipedia tells us there are 164,500 daily speakers.
  • Allow no-cache on back/forward navigations for https resources.
  • View and search open tabs from your smartphone or another computer in a sidebar.
  • Support for Google's Widevine CDM on Windows and Mac OS X so streaming services like Amazon Video can switch from Silverlight to encrypted HTML5 video.
  • Embedded YouTube videos now play with HTML5 video if Flash is not installed.

What changed in Firefox 47?

  • FUEL (Firefox User Extension Library) has been removed. Add-ons relying on it will stop working.
  • XRender is no longer used for rendering web content on Linux as this may cause a regression in remote X performance
  • The browser.sessionstore.restore_on_demand preference has been reset to its default value (true) to avoid e10s performance problems. Because faster is better!
  • The Firefox click-to-activate plugin whitelist has been removed.

What changed in Firefox 47 developer tools?

  • Start button for service workers in about:debugging to start registered Service Workers.
  • Changes that can affect add-on compatibility.
  • Smart multi-line input in the Web Console.
  • Added support for ChaCha20/Poly1305 cipher suites.
  • Web platform changes.
  • View, start,and debug registered Service Workers in the Service Workers developer tool.
  • Custom user agents supported in Responsive Design Mode.
  • Simulate Push messages in the Service Workers developer tool.

What changed in Firefox 47 HTML, CSS, JavaScript, DOM, SVG, WebGL, WebRTC, HTTP, Networking, Security and Compatibility?

  • HTML5 cuechange events are now available on TextTrack objects.
  • WebCrypto: PBKDF2 supports SHA-2 hash algorithms.
  • WebCrypto: RSA-PSS signature support.
  • User-agent spoofing now possible from the responsive mode.
  • Retaining paths panel in memory tool.
  • Service workers and Push API debugging.
  • about:debugging dashboard for workers.
  • Cached requests are now shown in Network Monitor.
  • Support for cache storage in Storage Inspector.
  • Add ability to filter Storage Inspector entries.
  • Console now detects incomplete input and switches multi-line mode.
  • Updated breakpoint style in debugger.
  • Prevent panels from hiding in devtools automatically using the Browser Toolbox, to aid browser and add-on debugging.
  • Font inspector has been disabled by default in developer tools.
  • 3D view has been removed from developer tools.
  • Developer tools theme refresh
  • Disable the Font Panel in developer tools.
  • Support for the CSS ::backdrop pseudo-element has been added.
  • The case-insensitive modifier i (example: [var=val i]) for attribute selectors has been implemented.
  • The display-mode media feature is now supported.
  • The new ES2017 Object.values() and Object.entries() methods have been implemented.
  • As per the new ES2016 specification, the Proxy enumerate trap for statements has been removed.
  • The Array.prototype.indexOf() and Array.prototype.lastIndexOf() methods and their TypedArray equivalents have been updated to never return -0 as per the ECMAScript specification.
  • The property Document.scrollingElement has been implemented behind the pref dom.document.scrollingElement.enabled that defaults to false.
  • The IDBKeyRange.includes() method has been implemented.
  • The Request.Request() constructor can now accept a referrer option in its init object.
  • Support for the RTCIceServer dictionary has been updated.
  • Cache.add() and Cache.addAll() now raises a TypeError exception if the response status is not in the 200 range.
  • The Browser API, which extends the functionality of <iframe>s to allow the creation of frames for displaying web content using HTML.
  • Now WAV file with u-law compression encoding can be played.
  • Widevine Content Decryption Module provided by Google is available via the Encrypted Media Extensions API for use with MP4.
  • The default value of the Accept header for images is now / instead of image/png,image/;q=0.8,/*;q=0.5.
  • URL with the view-source: protocol don't open the View Source tool anymore when used from a Web page.
  • The Firefox click-to-activate plugin whitelist has been removed: only Flash doesn't need to be clicked to be activated.
  • The CSS tokenizer is now available in JavaScript for add-ons.
  • The FUEL JavaScript library, introduced back in Firefox 3, has been removed.

What security fixes and vulnerabilities were discovered and fixed in Firefox 47?

  • Network Security Services (NSS) vulnerabilities.
  • Java applets bypass CSP protections.
  • Information disclosure of disabled plugins through CSS pseudo-classes.
  • Entering fullscreen and persistent pointerlock without user permission.
  • Incorrect icon displayed on permissions notifications.
  • Use-after-free when textures are used in WebGL operations after recycle pool destruction.
  • File overwrite and privilege escalation through Mozilla Windows updater.
  • Partial same-origin-policy through setting through data URI.
  • Out-of-bounds write with WebGL shader.
  • Addressbar spoofing though the SELECT element.
  • Use-after-free deleting tables from a contenteditable document.
  • Buffer overflow parsing HTML5 fragments.
  • Miscellaneous memory safety hazards.

What wasn't fixed in Firefox 47?

  • Selenium WebDriver may cause Firefox to crash on startup, use Marionette WebDriver instead.
  • Known issue with old invalid paper size printing preferences (Bug 1276717).

Happy cross-browser testing in Firefox 47!