video: no yes!
transparency: yes
partial transparency: unsure (what does this mean?)
lossless: yes
lossy: yes
hardware decoding/encoding: unsure
other nice things about jxl:<li>supports progressive images</li><li>smaller than avif while being higher quality</li><li>lossless transcode from jpeg to jpeg xl, while making the image smaller</li><li>up to 32 bits/channel (avif only supports up to 12 bits/channel)</li><li>up to 4099 channels</li><li>no stupid maximum resolution (avif has a max number of pixels of 8912896 pixels, which is 4096x2176. though a max width of 8192 and max height of 4352. jxl has a max number of pixels of 2<sup>30-1)</sup></li><li>faster encode & decode, apparently</li>