alt Hacker NewsI'm sure this is right about all the technical things, but the stuff about the requirements of a format for the web misses the mark IMO.
Normal people don't pick an image format based on whether it is suitable on the web or not. They want a format that works everywhere. If I download or upload a photo I don't want to have to do a lossy format conversion. If I'm writing an image processing tool it would be great if I can make it just support one input format that everyone uses, rather than "web" formats and "non-web" formats.
So I think a large part of the attraction of JXL is that it is a single format that works both for 10000x10000 lossless scientific images, and for 256x256 lossy web photos. You don't have to be an image format expert any more. Just always use JXL.
Definitely a shame about the technical flaws listed here though - especially decode time.
Professional web developers want to create a great experience for their users, so they go beyond simply serving whatever comes off a digital camera.
As the article identifies, JPEG XL is kinda bad at certain types of images, whereas AVIF does well across the board, so if you feel compelled to pick a single format to use, AVIF would be a better choice, but it's definitely worth optimising your web images for the web.
Also, JPEG XL is two codecs bundled into one, VarDCT and Modular. So, even if you're picking JPEG XL as "the one codec", you're actually picking two, and you need to choose between them at encode time.