Comment by boutell

Are they switching it on in Android Chrome? That would complete the picture of at least baseline support... eventually... when a decent percentage of Android phones actually get that version.

But Safari (MacOS or iOS) still doesn't support the progressive rendering shown here, nor animation, if caniuse is up to date:

https://caniuse.com/jpegxl

Not to be a downer — it's one necessary step on the road.