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 Release

January 24, 2017

Version 51.0, first offered to Release channel users on January 24, 2017

We'd also like to extend a special thank you to all of the new Mozillians who contributed to this release of Firefox!


  • Added support for FLAC (Free Lossless Audio Codec) playback

  • Improved reliability of browser data sync

  • An even faster E10s! Tab Switching is better!

  • Added Georgian (ka) and Kabyle (kab) locales

  • A warning is displayed when a login page does not have a secure connection

  • Added support for WebGL 2, with advanced graphics rendering features like transform feedback, improved texturing capabilities, and a new sophisticated shading language

  • Firefox will save passwords even in forms that do not have “submit” events

  • Improved video performance for users without GPU acceleration for less CPU usage and a better full screen experience

  • Added a zoom button in the URL bar:

    • Displays percent above or below 100 percent when a user has changed the page zoom setting from the default
    • Lets users return to the default setting by clicking on the button
  • Users can view passwords in the save password prompt before saving them

  • Remove Belarusian (be) locale



  • Updated to NSS 3.28.1

  • Re-enabled E10s support for Russian (ru) locale

  • Use 2D graphics library (Skia) for content rendering on Linux