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.

39.0.3 Firefox Release

Version 39.0.3, first offered to Release channel users on 6 August 2015

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

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.