GIMP (GNU Image Manipulation Program) is a free and open-source graphics editor. Though it was initially developed as a Linux image editor, it has evolved into a powerful alternative to Adobe Photoshop while remaining accessible and open source.
GIMP is capable of reading WebP files and has recently added support for the new image format AVIF.
To this date, Gimp does not have native JPEG XL support in a release version. The development version 2.99 features JPEG XL support in the win64-nightly release.
Several plugins exist that claim to add JPEG XL support. However, we didn't find a plugin that was fully working, responsive, or easy to install for a regular end user during our testing.
If you're nerdy and would like to dive deeper into the topic, we recommend the following:Gimp JPEG XL Plugin by novomesk JPEG XL plugin for GIMP 2.10.24 by xiota