cjxl

Compress images to JPEG XL. Accepted input extensions are PNG, APNG, GIF, JPEG, EXR, PPM, PFM, PAM, PGX, and JXL. More information: https://github.com/libjxl/libjxl.

• Convert an image to JPEG XL:

cjxl path/to/image.ext path/to/output.jxl

• Set quality to lossless and maximize compression of the resulting image:

cjxl --distance 0 --effort 9 path/to/image.ext path/to/output.jxl

• Display an extremely detailed help page:

cjxl --help --verbose --verbose --verbose --verbose