Mozilla Firefox version 152.0 was released a few days ago. (As of the time of writing, it is now 152.0.1)
Starting with this version, the next-generation image format JPEG-XL (JXL) has been included as an experimental feature.
As shown below, you must enter the experimental features page and activate it directly.
The settings screen has also been redesigned. The structure has been simplified and the categories have become clearer.
Please refer to the original release notes for the rest of the details.
https://www.firefox.com/en-US/firefox/152.0/releasenotes/
