Firefox 140.0.4

Firefox's QUIC stack is moving to a Rust based UDP I/O stack that leverages various modern, operating system specific calls, resulting in improved HTTP/3 upload and download performance. This feature is part of a progressive roll out. What is a progressive roll out? Certain new Firefox features are released gradually. This means some users will see the feature before everyone does. This approach helps to get early feedback to catch bugs and improve behavior quickly, meaning more Firefox users overall have a better experience.

Fixed incorrect font selection in some cases when attempting to use color fonts. ( Bug 1971053 )

Fixed the search results not updating when switching source during a file search in the Developer Tool's debugger. ( Bug 1971094 )

Reference link to 140.0.2 release notes .