[REVISION HISTORY]
Mozilla Firefox 155 and 156 software releases
Updated 1 time since CLSTR started tracking revisions of this situation.
What changed
2026-09-05 08:36 UTC → 2026-09-16 13:48 UTC ·
added
removed
Mozilla Firefox 155 software release and updates 156 software releases
Mozilla released Firefox 155, which introduced networking and privacy enhancements. Technical updates included the implementation of Happy Eyeballs v3 to reduce connection delays and support for QUIC version 2 to improve HTTP/3 efficiency. Privacy updates featured a visible tracker counter in the address bar and reorderable Firefox Containers. Following the initial release, Mozilla issued Firefox 155.0.1 as a maintenance update to resolve several bugs. This update addressed issues such as browser freezes on websites using specific CSS filters, sidebar visibility errors, and display bugs in account menus. A known issue regarding washed-out video formats on macOS was noted as being addressed in a future version. With the release of Firefox 156, Mozilla has transitioned to a biweekly update cycle. This version emphasizes performance optimizations, including a built-in PDF viewer that starts up to 45% faster and more efficient handling of large JPEG images. By utilizing libjpeg-turbo’s IDCT scaling, the browser can reduce memory usage by up to 20% and double decoding speeds when resizing high-resolution photos. New features include sponsored suggestions in the address bar via Firefox Suggest, currently active in France, Germany, and Italy, though users can opt out via settings. Technical fixes in this release address connectivity problems with the built-in VPN or DNS over HTTPS, subtitle errors in Picture-in-Picture mode, and improved hardware H.264 decoding for WebRTC video calls on Windows ARM64 devices. Additionally, macOS users can now set Firefox to launch automatically upon system startup.
Versions
- 2026-09-16 13:48 UTC Mozilla Firefox 155 and 156 software releases
- 2026-09-05 08:36 UTC Mozilla Firefox 155 software release and updates
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