Firefox Beta and Developer Edition
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 Beta — English (US)

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

Firefox Beta — English (US)

Firefox Beta 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

Download a different build

Firefox Beta 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

149.0beta Firefox Beta

Version 149.0beta, first offered to Beta channel users on February 25, 2026

Firefox Beta gets updated 3 times a week and as a consequence, the release notes for the Beta 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 via the Firefox Trains website or our @FirefoxBeta Bluesky account.

Increased robustness of HTTP/3 upload performance for unstable network conditions.

Developer Information

The new Reporting API provides a generic reporting mechanism for web applications to use to make reports available based on various platform features (for example Content Security Policy, Permissions-Policy, or feature deprecation reports) in a consistent manner.