Firefox Release Notes

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.

Download Firefox — English (US)

Your system may not meet the requirements for Firefox, but you can try one of these versions:

Download Firefox — English (US)

Firefox is no longer supported on Windows 8.1 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

Firefox is no longer supported on macOS 10.14 and below.

Please download Firefox ESR (Extended Support Release) to use Firefox.

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
Users can view passwords in the save password prompt before saving them
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
Improved video performance for users without GPU acceleration for less CPU usage and a better full screen experience
Firefox will save passwords even in forms that do not have “submit” events
Added support for WebGL 2, with advanced graphics rendering features like transform feedback, improved texturing capabilities, and a new sophisticated shading language
A warning is displayed when a login page does not have a secure connection
Added Georgian (ka) and Kabyle (kab) locales
An even faster E10s! Tab Switching is better!
Improved reliability of browser data sync
Remove Belarusian (be) locale