See what landed recently in Firefox Nightly!

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 21, 2020

Version 83.0a1, first offered to Nightly channel users on September 21, 2020

Firefox Nightly gets updated 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.

Warning: 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.


  • A major update to Firefox JavaScript JITs engine (codenamed Warp) is now activated by default on the nightly channel and brings some nice speed improvements. If you find any issues, please file bugs blocking bug 1613592 .

    Bug 1666417
  • WebRender is now activated on Intel Gen12 GPUs

    Bug 1667149


  • HTTP authentication prompt dialogs are now tab-modal instead of window-modal

    Bug 613785
All Firefox Nightly downloads