Mozilla releases Firefox 155 with networking and privacy updates

Mozilla has released Firefox 155, introducing several networking and privacy enhancements. A key technical update is the implementation of Happy Eyeballs v3, which allows the browser to attempt multiple network connection paths in parallel. By using the path that responds first, the browser can reduce delays caused by unstable IPv4 or IPv6 connections. The update also adds support for QUIC version 2 (RFC 9369) to improve HTTP/3 connection efficiency.

Privacy features have been updated to include a visible tracker counter in the address bar, showing the number of blocked trackers on a page. Users can choose to hide this counter for a cleaner interface without disabling the underlying protection. Additionally, Firefox Containers can now be reordered within the Settings menu, with changes reflecting throughout the browser.

The release includes various platform-specific fixes. Linux users will see resolutions for issues regarding system sleep modes and text disappearing in web applications like Microsoft 365 Word Online. On Windows, support for Nintendo Switch Pro controllers and compatible third-party controllers has been improved for browser-based gaming. Other fixes address background audio streaming stability and printing capabilities for small PDF files.