Download Firefox

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.

Firefox Privacy Notice

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.

127.0a1 Firefox Nightly

April 15, 2024

Version 127.0a1, first offered to Nightly channel users on April 15, 2024

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, our Mastodon account as well as read our Nightly Blog.

You can interact with other Firefox Nightly users and give your feedback to Mozilla staff in the Nightly Matrix room on


  • Starting with Firefox 124, a simpler and more unified dialog for clearing user data is now available in Nightly builds. In addition to streamlining data categories, the new dialog also provides insights into the site data size corresponding to the selected time range.

    Bug 1874702
  • Starting with Firefox 125, Nightly builds support resolving HTTPS DNS records with the operating system's DNS resolver on specific platforms (Windows 11, Linux, Android 10+) without requiring DNS over HTTPS to be enabled. This capability allows the use of HTTP/3 without needing to use the Alt-Svc header, upgrades requests to HTTPS when the DNS record is present, and enables wider use of ECH. This feature is expected to ship in Firefox 126.

    Bug 1874464

Web Platform

  • Starting with Firefox 125, the transition-behavior CSS property is now supported in Nightly builds.

    Bug 1805727
  • Starting with Firefox 125, Nightly builds will attempt to establish TLS connections using a hybrid post-quantum key agreement mechanism (X25519+Kyber768). This may result in slow TLS handshakes or failed connections on networks with TLS intercepting middleboxes. The feature can be disabled by setting the security.tls.enable_kyber preference to false.

    Bug 1878725

Get the most recent version

All Firefox Nightly downloads