See what’s new in Firefox!

Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system requirements of this release.


Firefox Aurora

May 2, 2014

Version 31.0a2, first offered to Aurora channel users on May 2, 2014


  • Integration of generational garbage collection

  • Add the search field to the new tab page

  • mozilla::pkix as default certificate verifier (learn more)

  • OdinMonkey: Use backtracking allocator for asm.js style code

  • Partial implementation of the OpenType MATH table (section 6.3.6) see documentation about mathematical fonts and the MathML Torture Test for details

  • audio/video .ogg and .pdf files handled by Firefox if no application specified (Windows only)


  • navigator.sendBeacon enabled by default (learn more)

  • New Array built-in: Array.prototype.fill() (learn more)

  • New Object built-in: Object.setPrototypeOf() (learn more)

  • CSP 1.1 nonce-source and hash-source enabled by default

  • Developer Tools: Eyedropper tool added to the color picker (learn more)

  • Dialogs spawned from the onbeforeunload event no longer block access to the rest of the browser

Developer Information


  • Without affecting security, after restoring your session, Extended Validation Certificates might not display (See 995801)


  • Exit is not always completed when "clear history when Firefox closes" is enabled (1005487)

  • Mac OS X: cmd-L no longer opens a new window when no window is available (1008793)

  • Slow shut downs lead to 'Firefox is already running' warning (see 966469 and 985655)