What Is JPEG XL?
JPEG XL is a modern image format β file extension .jxl β built to replace JPEG. It makes noticeably smaller files at the same quality, and it does things JPEG never could: transparency, animation, HDR and true lossless. It is royalty-free and standardised as ISO/IEC 18181.
by Robert Castillo Β· Published Β· updated
The short version
Every image format is a trade between how small the file is, how good it looks, and how many programs can open it. JPEG has been winning the third one since 1992 while steadily losing the first two.
JPEG XL was designed to take the first two decisively without throwing away what made JPEG useful. It came out of two projects that merged in 2018 β Google's PIK and Cloudinary's FUIF β and was finalised as an international standard. Crucially, it is royalty-free, with no licensing body to pay, which is a large part of why people wanted it to win.
The catch is the third trade. A format is only as good as the software that opens it, and that is where JPEG XL is still catching up. The biggest step came in October 2026: Chrome 155 switched it on by default on 6 October, and Firefox 158 followed on 13 October. Microsoft Edge still doesn't show it.
What JPEG XL actually does
Smaller at the same quality
Typically well under half the size of the equivalent JPEG for photographs, and it degrades far more gracefully β no blocky artefacts when you push it hard.
Lossless JPEG re-packing
Its best trick. Feed it an existing JPEG and it repacks the same data about 20% smaller, then reconstructs the original file byte for byte on demand. Nothing is lost, so there's no reason not to.
One format, every job
Lossy photos, lossless graphics, transparency, animation β all in one format. Today that means JPEG plus PNG plus GIF plus WebP.
HDR and wide gamut
Up to 32 bits per channel and modern colour spaces, so it holds what a phone or a proper camera actually captures instead of clipping it to 8-bit sRGB.
Progressive by design
A blurry-but-complete image appears from the first bytes and sharpens as the rest arrives, rather than loading top to bottom.
Very large images
The format's limits run to a billion pixels per side, so gigapixel panoramas and scanned artwork stay in one file.
JPEG XL compared with the formats you already use
| Feature | JPEG | PNG | WebP | JPEG XL |
|---|---|---|---|---|
| Lossy compression | Yes | No | Yes | Yes |
| Lossless compression | No | Yes | Yes | Yes |
| Transparency | No | Yes | Yes | Yes |
| Animation | No | No | Yes | Yes |
| HDR / more than 8-bit | No | Yes | No | Yes |
| Re-packs existing JPEGs losslessly | β | No | No | Yes |
| Opens everywhere today | Yes | Yes | Yes | Not yet |
That last row is the whole story. On the technical merits JPEG XL wins the table; on the only row that matters to a stranger receiving your file, it loses. For a deeper look at the closest comparison, see JPEG XL vs WebP.
So should you use it?
Yes β for your own storage
Photo libraries, backups, archives. You control what opens them, and the lossless JPEG re-packing gives you roughly 20% of your disk back with zero quality cost and no lock-in.
Careful β on a website
Chrome 155+, Firefox 158+ and Safari 17+ show a .jxl, but Edge doesn't, and nor does any browser that hasn't been updated. Use it only inside a <picture> element with a WebP or JPEG fallback. Test your own browser.
Where you'll run into .jxl files
Long before Chrome and Firefox switched it on, JPEG XL had been quietly adopted where file size and fidelity matter more than universal compatibility. Apple supports it across Safari and macOS. Adobe uses JPEG XL compression inside modern DNG camera raw files. The PDF Association made it the preferred format for HDR images in PDF. Camera and scanning workflows use it for archival masters.
Which is how most people meet the format: not by choosing it, but by being handed a .jxl that won't open. If that's you, here's how to open it on any device.
FAQ
What does JXL stand for?
.jxl and the MIME type is image/jxl.Is JPEG XL the same as JPEG 2000?
.jp2) is a much older, unrelated format that never caught on outside specialist fields like medical imaging and cinema. JPEG XL is a separate design from 2018 onwards.