Firefox Nightly
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.

Firefox Nightly

September 22, 2017

Version 58.0a1, first offered to Nightly channel users on September 22, 2017

Firefox Nightly gets a new version every day and as a consequence, the release notes for the Nightly channel are updated continuously to reflect features that have reached sufficient maturity to benefit from community feedback and bug reports. Features listed here may or may not make a final release of Firefox.

In addition to these release notes, you can follow ongoing development on our @FirefoxNightly Twitter account as well as read our Nightly Blog.


  • WebVR has been enabled for Mac OS X users

    Bug 1374399
  • Video decoding is disabled when not visible, providing both performance and limited battery usage

    Bug 1401909
  • Optimize page load by caching JavaScript internal representation. Read the Blog post.

    Bug 1405738
All Firefox Nightly downloads