It's a pretty stylish and parsimonious file extension even if long file extensions are well-supported (and they are), but I think *.jpegxl should also be recognized. Have a feeling it will be de facto recognized eventually, if the format itself gets traction.

I like JXL better than Jpeg XL - if it is brought to the masses I can imagine "jexel" to replace "jaypeg"

The extension for the file format is .jxl and is pronounced "jixel" :)

It's hilarious to me that 25ish years after the death of DOS, we still define dot-three-letter file extensions in new standards.

Right?

Well, at least in the tiny part of the IT world I get to control, I always try to validate based on both the three letter extension and any common or sensible expansion of that. So ".jpg" or ".jpeg", ".jxl" or ".jpegxl" etc. etc. (And in most cases, I actually try to parse the binary itself, because you can't trust the extension much anyway.)

"I thought we were free to choose our filename extensions to our liking?"

"Well, three characters is the bare minimum. If you feel that three characters is enough, then okay. But some people choose to have longer filename extensions, and we encourage that, okay? You do want to express yourself, don't you?"

Especially funny since JPEG images commonly have .jpeg as an extension!

If it ain't broke...

Ah, following the footsteps of .png (which is pronounced ping, according to the standard)

I actually think it referencing JPEG is smart as it's immediately recognizable even by regular users as "image" and positions the format as a successor.

JPEGX or JPEG2 would be more marketable than JPEG XL.

TBH I just don't see a difference.