Yes, a hdr photo in heif or jxl is a night and day difference. And if you apply any kind of color edits to the photo it stretches the colors to the point visible banding occurs on jpeg.

You can very easily see ugly banding if you try to use an 8 bit format to store HDR images, and that's all you get with normal jpeg.

Yes, and image editors absolutely can. If JXL lets me correct over/underexposed images by default everywhere I find them then it's worth it even just for that reason alone

> Can the human eye even tell the difference? This feels like 8k vs 4k tv.

Even if it cannot, getting the same quality as 'classic' JPEG in fewer bits is still useful. So you have:

* better quality in the same number of bits

* same quality in fewer bits

On an ecommerce site? Who cares. On instagram or anywhere people share photos? Amazing.

Bottom line it can deliver greater quality at much smaller filesizes. Considering RAM and storage are more expensive per byte now than they have been in years, I think it's incumbent on everyone in a position to do so, to use those resources wisely.

WebP and AVIF and HEIC had similar advantages but also some disadvantages (honestly chief disadvantage to WebP in my humble opinion was that nothing except web browsers -- to this day -- seem to support it!).

Another important point in its favor is that JPEG XL is designed as a royalty‑free, open standard, and Google provides a perpetual, worldwide, royalty‑free patent license for its reference implementation.

Avoiding JXL (once the rollout is sufficiently complete) seems, to me, like still shipping (non-animated) .GIF files where .PNG is better and smaller.

It looks fine sure, but that doesn't make it good either. Are you going to lock display technology to 8 bit forever? Most PC monitors already match or exceeding that limit, phones especially. HDR is something that needs to happen eventually, and for that new format is very important