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Comment by llm_nerd | Hacker News Reader

What do you think doesn't support it?

Affinity supports it. Photoshop supports it. Microsoft Photos supports it. Gimp supports it. Apple has had systemwide support for it since iOS 17+ / macOS 12+, including in Safari and basically any app that uses the system image functions.

Chromium isn't on the bleeding edge here. They actually were when it first came out, but then retreated and waited, and now they're back again.

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Half the point of JPEG XL is support for HDR and higher than 8 bits per channel. Most of the apps you listed don’t support that fully, especially iOS, which converts everything to SDR or shows garbage — except for their own proprietary gain map encoding that their camera app produces.

Actually, in my recent vibe coding adventures I tested making a ProRAW converter app that also applied the included gain map to the image and encoded via libjxl on device. Surprisingly, Photos.app was able to display the converted image with HDR, but the HDR tag in the UI is only displayed for images with the proprietary gain map.

There seems to be some support there, though I tested on iOS 26.

Yes, but you can't send that to anyone via iMessage. It corrupts the image.

That I of course didn't test. Yeah, I'd expect them reencoding images to save on bandwidth, and they're probably doing so naively for JXL (maybe even converting to HEIC).

> That I of course didn't test.

Neither did Apple, which is the problem!

Lots of stuft still doesn't support it, for example WhatsApp and Discord.

WhatsApp doesn't even support WebP though. Hopefully, if they ever get around to adding WebP, they'll throw JXL in, too.

Discord certainly supports it (on web and desktop client). I've been able to upload high resolution WebP images for at least a year now.

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