JPEG XL: The Next Image Format, Explained

0:00"We got JPEG-2 before GTA 6." It's not literally called JPEG-2, but the image format JPEG XL (.jxl) is — in ThioJoe's read — the most plausible candidate to become the next image format we all use. The reason to care right now: it just landed in Chrome stable.

What JPEG XL is

1:07JPEG XL compresses far smaller than plain JPEG while preserving quality, and it's smaller than WebP too. But the real argument is breadth: it packs a feature set that neither JPEG nor WebP nor PNG fully matches — transparency, high bit depth, lossless mode, animation, HDR, and more. The important framing in the video: unlike WebP (which browsers supported for years while operating systems didn't, leaving users furious when a downloaded image wouldn't open), JPEG XL already has OS support — "it will not be like the infamous WebP."

The Chrome 155 milestone

0:24The news hook: JPEG XL was added to Google Chrome stable. Chrome 155 ships decoding for .jxl by default, Firefox 158 has it too, and Safari (macOS and iOS) has supported it for a while. On operating systems it's already in macOS and Windows — on Windows via a free, official Microsoft Store extension. So the last major holdout, Chrome, has finally come around — a U-turn Google announced back in November 2025, after Chrome removed an earlier experimental JPEG XL support back in early 2023. (The video notes Microsoft Edge, despite being Chromium-based, didn't seem to have it yet at recording time — "I assume they'll add it pretty soon.")

The feature set

1:26Features in the spec that plain JPEG lacks: transparency (an alpha channel); more than 8 bits per channel (8-bit is 256 levels ≈ 16 million colors, JPEG XL goes well past that); optional lossless compression (JPEG is lossy-only, JXL can behave like PNG); animation; and HDR. 1:59Two less common ones: regions of interest — when saving, you mark the most important part (the subject) and compression quality is concentrated there, so "for any given file size, it'll focus the data where you most want it" — and tiling, where independent tiles let you load only part of a very large image, or decode multiple tiles in parallel across cores. PNG and WebP, while richer than JPEG, still don't do HDR, regions of interest, or tiling.

Compression

3:00There's a JPEG XL test page on jpeg.org that shows whether your browser renders embedded JXL images, along with a quality score and file size. In that test, JPEG XL came out smaller than every other compressed format across the board — expected against lossless PNG, but it also beat WebP. Google's own announcement frames it as "30–50% better compression than JPEG."

Lossless JPEG↔JXL

3:29A subtle but genuinely useful property: you can losslessly convert an existing JPEG to JPEG XL. It won't recover detail that a low-quality JPEG already lost, but the JXL will be smaller for that same quality — effectively free compression. And you can convert back to JPEG later without further loss. That makes JXL compelling for archiving: re-encode a whole library of JPEGs to JXL, save the space, and convert back if compatibility ever demands it. One caveat he stresses: it's not backwards-compatible — the app or OS has to support JPEG XL specifically, so you can't just rename a .jxl to .jpg and expect it to open everywhere.

The competition: AVIF

6:16The other modern contender is AVIF, based on the same compression under the hood as the AV1 video codec. It has had near-universal browser support for a while and, in many cases, even better compression than JPEG XL. But his skepticism: it's "basically only used on the web," and downloading an AVIF is "always really annoying, just like WebP was." On Windows it needs two extra Microsoft extensions (HEIF Image Extensions and AV1 Video Extension). His argument for why JXL will win the mindshare battle is almost branding: "having that JPEG part of the name, it's just a little bit more understandable — 'oh, it's just a new version of JPEG.' That's a lot easier of a pill to swallow than an AVIF weird file extension you've never heard of."

Will it become ubiquitous?

8:06His honest assessment: it comes down to general software support. OS support is the essential floor — "if you send it to someone, they have to be able to at least see it" — but apps matter too, because people want to use the image in editors and documents, not just view it. The pragmatic play now: use JXL where the payoff is clearest — archiving, or very large images where space matters — and, when a program doesn't support it, ask the developer to add it ("it's already in Windows, it's already in Chrome, everyone's using it"). With Chrome finally in, the momentum argument is easier to make than it's ever been. 9:09Realistically: early adopters first, then a slow grind toward "common."

Claims checked

Sources & further reading