JXL can do lossy images (like JPEG) and lossless ones (like PNG), and on average it'll produce smaller file sizes than both (While beating JPEG quality wise). The killer feature is that it can do lossless recompression of existing JPEG files and shave off about 20% of the file size, and it's reversible so you can turn those JXL files back into JPEG images for existing software.

The downside is that it was created by Google Research (among others), but the Chrome team made AVIF instead and decided that's what they'd support and nothing else.

At least Safari supports it.

AVIF is generally smaller in size than both WebP and PNG. AVIF supports animation while PNG does not.

The lossless mode in AVIF is so bad that a BMP in a ZIP file produces smaller results.

Which makes sense, as it doesn't actually have a dedicated lossless mode (like WebP does), the encoder is just to not quantise the video data it produces.

Probably still more supported than Webp and Webm

Yep, it was one of the ways to have an animated avatar on BB forums.

Most recently, I have seen them being used in animated chat stickers (like on Signal).

Would this be the Gif killer? If PNG can contain a relatively similar frame count & time limit but with marginally better image quality it just may.

It's great that Papua New Guinea is still receiving updates /s

That’d be the browser’s (or whatever app you’re using) fault, not the format. I guess you could choose to hate it for poor support.

That was because they added 'shorts' and friend-lists to it.

So it depends on the specific HDR encoding used, Rec2020 is the most common ones you'll see (It's meant for "pure" setups, i.e. where the source and output are tightly linked, e.g. gaming consoles or blu-ray, or so) and the raw data won't look great. While something like HLG (Hybrid-Log Gamma) is designed for better fallback (As it's meant for TV broadcast, where the output device is "whatever TV the user has"), so should just look dimmer.

This is a HDR screenshot I took of Destiny 2, which uses Rec2020, tone mapped to SDR

And here's the raw screenshot data from before tonemapping.

If the second image had all the right HDR metadata, and the viewer supported it properly, then both images would match.

lossless recompression of existing JPEG
Uh… how does it make a JPEG lossless? Or is it lossless in that it makes a JXL out of a JPEG without affecting the original JPEG quality (i.e. no further loss beyond JPEG's)?

Being able to turn JPEGs into JXLs and JXLs back to JPEGs is cool, though

What's with the AVIF thing? Yet another I am unfamiliar with (all I know about image formats is JPG = worse quality, PNG = better quality, GIF = animated (and something WebP. Idk much about that one either))

Also, in my research, I've found something about the distinction between lossless JXL vs lossy JXL. Seems like you wouldn't be able to tell if the image is lossy or lossless just from it being a JXL