The flag also hasn't seemed to do be able to do anything in some update rings for a while now, so will be considering this a flag implementation bug --that is tied to the original issue of JPG-XL (.jxl) Format/Content Support across the various OS Platforms that Mozilla products are supported on. (macOS/iOS, Linux/Android/ChromeOS, MS Windows etc)

Are there any blockers? Chromium has already started testing with the same jxl-rs.

We have a re-write of most of our C++ wrapping code to support progressive rendering in bug 2023488, and then we want to do some fuzzing of our implementation to make sure there is nothing that we missed then we plan to ship the jxl code to beta and release.

https://hg.mozilla.org/mozilla-central/rev/3f29dd8d7447

Not sure the best avenue for this. The jpeg xl image codec will now be available for testing behind a disabled-by-default pref image.jxl.enabled on release and beta, before this it was only available to try on nightly. Maybe a note for developers? Like https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/149

Release Note Request (optional, but appreciated)
[Why is this notable]: new image decoder for jpeg xl
[Affects Firefox for Android]: yes
[Suggested wording]: The JPEG XL image decoder is now available for testing and can be enabled using the image.jxl.enabled preference.
[Links (documentation, blog post, etc)]: https://jpeg.org/jpegxl/

(In reply to Timothy Nikkel (:tnikkel) from comment #7)

Not sure the best avenue for this. The jpeg xl image codec will now be available for testing behind a disabled-by-default pref image.jxl.enabled on release and beta, before this it was only available to try on nightly. Maybe a note for developers? Like https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/149

Release Note Request (optional, but appreciated)
[Why is this notable]: new image decoder for jpeg xl
[Affects Firefox for Android]: yes
[Suggested wording]: The JPEG XL image decoder is now available for testing and can be enabled using the image.jxl.enabled preference.
[Links (documentation, blog post, etc)]: https://jpeg.org/jpegxl/

I am guessing that this will be available in Firefox Labs? We have a new Firefox Labs section in our release notes for experimental features.

(In reply to Pascal Chevrel:pascalc from comment #8)

(In reply to Timothy Nikkel (:tnikkel) from comment #7)

Not sure the best avenue for this. The jpeg xl image codec will now be available for testing behind a disabled-by-default pref image.jxl.enabled on release and beta, before this it was only available to try on nightly. Maybe a note for developers? Like https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Releases/149

Release Note Request (optional, but appreciated)
[Why is this notable]: new image decoder for jpeg xl
[Affects Firefox for Android]: yes
[Suggested wording]: The JPEG XL image decoder is now available for testing and can be enabled using the image.jxl.enabled preference.
[Links (documentation, blog post, etc)]: https://jpeg.org/jpegxl/

I am guessing that this will be available in Firefox Labs? We have a new Firefox Labs section in our release notes for experimental features.

Yes I think so. I think the MOZ_JXL define should put it in Firefox Labs on the beta channel automatically. I'm working on understanding exactly what is all entailed by Firefox Labs/experiemental features and any connection to nimbus.

FYI, jpegxl isn't in Firefox Labs on 152.0b1 build1 as far as I can tell.

I talked to Beth last week about this, and I just followed up to see where we are at in getting experiments for beta and release going.

Yes, I think we should have jxl available in Firefox labs now, I believe that work is complete now.

(In reply to Timothy Nikkel (:tnikkel) from comment #12)

Yes, I think we should have jxl available in Firefox labs now, I believe that work is complete now.

I just checked and yes, it is available in 152beta9

Note added to Note added to our 152 beta release notes in the Firefox Labs section with this wording:

Firefox now supports the new JPEG XL image format which generally has better compression than WebP, JPEG, PNG and GIF and is designed to supersede them. This is an experimental feature that can be enabled from the Firefox Labs panel in Settings.

The related MDN doc updates can be tracked in https://github.com/mdn/content/issues/44418

(In reply to Pascal Chevrel (relman team) -> :pascalc from comment #14)

Note added to Note added to our 152 beta release notes in the Firefox Labs section with this wording:

Firefox now supports the new JPEG XL image format which generally has better compression than WebP, JPEG, PNG and GIF and is designed to supersede them. This is an experimental feature that can be enabled from the Firefox Labs panel in Settings.

The first sentence sounds like jxl is enabled by default, the second sentence clarifies. It would be good if one didn't need to read the second sentence or be left with a false impression.

(In reply to Timothy Nikkel (:tnikkel) from comment #16)

The first sentence sounds like jxl is enabled by default, the second sentence clarifies. It would be good if one didn't need to read the second sentence or be left with a false impression.

Updated.

Firefox now offers experimental support for the new JPEG XL image format, which generally provides better compression than WebP, JPEG, PNG, and GIF and is designed to supersede them. You can enable it from the Firefox Labs panel in Settings.