Oh yeah, definitely. For me the usecase is infinite scrolling, where you buffering offscreen images to allow you to continually flick through an image feed with

Oh yeah, definitely. For me the usecase is infinite scrolling, where you buffering offscreen images to allow you to continually flick through an image feed without having to "wait" for a preview to appear. Although you can do this without JXL, its a much more fluid experience with the progressive download - especially if you micromanage the behaviour of the network requests (i.e. progressive throttling of offscreen images past first frame). Lower filesize over JPEG is also a benefit there as you can more quickly resume the load of the higher fidelity frames when in view. Current browser support where available is a lot more restrictive TBH, as you dont have any control over that behaviour. But outside the browser its solid gold.