Firefox 159 fixes Wayland tab detachment bugs, enables sidebar passwords by default

Mozilla has released Firefox 159, the latest version of its open-source browser now shipping on a twice-monthly cadence. The release makes the Passwords sidebar tool visible by default, adds a Ctrl+Shift+A keyboard shortcut for tab search, and introduces scroll-driven CSS animation support for web developers.

For Linux users specifically, Firefox 159 fixes two Wayland compositor bugs that caused erratic tab behavior: tabs could incorrectly detach when simply clicked, while intentional upward drags to detach tabs would fail. The release also resolves excessive memory usage on AMD GPU systems when sites like ChatGPT display Mapbox GL JS maps, and includes cherry-picked patches for improved Vulkan ffvpx media handling on Linux.

Wayland and Linux-specific fixes in Firefox 159

• Wayland tab detachment: Clicking a tab no longer incorrectly triggers detachment into a standalone window on Wayland compositors, while dragging a tab upward now properly detaches it as intended.
• AMD GPU memory fix: Resolved excessive memory consumption on Linux systems with AMD GPUs when Mapbox GL JS maps are rendered, particularly affecting sites like ChatGPT.
• Vulkan ffvpx improvements: Cherry-picked patches enhance Vulkan-based hardware-accelerated video decoding through the ffvpx media backend on Linux.
• Scroll-driven animations: New CSS feature support allows web developers to bind animation progress to scroll position or element viewport traversal.
• Auto-PiP preview: A hidden enable-when-occluded preference in about:config enables automatic picture-in-picture when video-playing tabs are obscured by other windows or browser minimization.

Why it matters

The Wayland fixes address real usability pain points for Linux desktop users who have experienced Firefox as a rougher citizen on modern compositors compared to X11. For distributions shipping Firefox as a default browser, including Ubuntu via Snap, these fixes reduce support burden and improve the out-of-box experience on GNOME and other Wayland-first environments. The AMD GPU memory fix is particularly relevant for users of AI and mapping-heavy web applications where browser memory pressure can degrade overall system performance.