"Your browser does not support JPEG XL"; I'm sure it's cool technology but whoever is behind it needs to hire developers and advocates to push code to Webkit / Blink to add support for it, else it won't get mainstream adoption.
Chrome: behind a flag since version 91.0.4470.0
Firefox: behind a flag since version 90.0a1
Edge: behind a flag since version 91
Opera: behind a flag since version 77
ImageMagick: since version 7.0.10-54
XnView MP: since version 0.97.0
ImageGlass: since version 8.1.4.18
ExifTool: since version 12.23
gThumb: since version 3.11.3
OpenMandriva Lx: since version 4.3 RC
GIMP: since version 2.99.8
qimgv: since version 1.0.0
PhotoQt: since version 2.4
jxl-winthumb: with WIC-codec since version 0.1.11
KImageFormats: since version 5.89.0It's in my to do-list in the coming weeks, I have not verified this yet.
I really wish it stop behaving like IE by being on its own.
I really hope it takes off. There was a bit poor timing because widespread AVIF support happened _right_ before and now we need to beg browser vendors to adopt JPEG XL! I hope they don't balk at it for starting introduce too much file format cruft because JPEG XL is really, really something they should implement. It can succeed JPEG as well as PNG (lossless JPEG XL tend to destroy even optimized PNG). I'd much rather abandon AVIF support. It's just one of those annoying single-video-frame-as-a-picture hacks like WebP and HEIF without drive to make them outstanding image formats on their own for photography as well as line art.