Firefox Beta and Developer Edition
Release Notes

A major update to Firefox JavaScript JITs engine (codenamed Warp) is now activated by default and brings some nice speed improvements. If you find any issues, please file bugs blocking bug 1613592 .

WebRender is now activated on Intel Gen12 GPUs

There is now a "Print selection" context menu item.

Device sharing state indicator icons have been added to the system tray on Windows

Users with touchscreens and precision trackpads can now use pinch gestures on those devices to zoom web content without reflowing

Added an option in about:preferences to disable control of media via keyboard, headset and virtual interface.

Fix for MFSA 2020-49 included in version 83.0b10 and newer.

For users on macOS with minimized windows, Firefox now uses much less power and you should see much longer battery life.

HTTP authentication prompt dialogs are now tab-modal instead of window-modal

You can now click on the "scroll" badge for scrollable elements to toggle highlighting of the overflow causing elements, which also have a new "overflow" badge next to them

Added support for CSS conic gradients