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 — English (US)

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

Firefox Nightly — English (US)

Firefox Nightly is no longer supported on Windows 8.1 and below.

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

Download Firefox ESR 64-bit

Download Firefox ESR 32-bit

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Firefox Nightly is no longer supported on macOS 10.14 and below.

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

Download Firefox ESR

Firefox Privacy Notice

Version 69.0a1, first offered to Nightly channel users on May 20, 2019

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.

Firefox will give Windows hints to appropriately set content process priority levels, meaning more processor time spent on the tasks you're actively working on, and less processor time spent on things in the background (with the exception of video and audio playback).
Bug 1548364
Finder on macOS now displays download progress for files being downloaded.
Bug 909760

The “Always Activate” Flash option was removed. Firefox will always ask for user permission before activating Flash on a website.
Bug 1519434
Users who use userChrome.css or userContent.css files to customize Firefox may need to flip the toolkit.legacyUserProfileCustomizations.stylesheets pref to true in order for Firefox to load these files. This is to avoid touching the disk unnecessarily during start-up for users that don't have those files. This pref will have been set automatically for users on Firefox 68 who had either userChrome.css or userContent.css already exiting in their profile directories.
Bug 1541233