JXL

Compress JPEG XL

Up to 100 files at once. Mixed formats are fine.

Compressing a JPEG XL re-encodes it at a lower quality, in your browser, with nothing uploaded. JXL is the most capable of the formats here and the least widely supported — worth knowing before you commit a collection to it.

Designed for archives, not for web pages

JPEG XL came out of a competition to replace JPEG properly, and its priorities show: it encodes far faster than AVIF at similar sizes, supports images beyond what a screen can display, and can repack an existing JPEG losslessly at around a fifth smaller — the original recoverable byte for byte.

That last capability is unique and is what makes it interesting for archives. It is not what this page does, which is ordinary lossy re-encoding, but it is worth knowing that a JPEG collection can be shrunk without any loss at all by a tool built for it.

The support problem

Browser support is the unresolved part. Safari ships it, Chrome removed it after shipping it behind a flag, and Firefox has not enabled it. Photoshop and several professional tools read it; most consumer software does not.

For a website, that rules it out — you would be serving a format most visitors cannot display. For a personal archive on your own disk, where you control what opens the files, the calculation is different and JXL is a reasonable bet.

How to compress a JXL

  1. Drop your JXL onto this page, or click to choose one.
  2. It is re-encoded at the quality shown, in your browser.
  3. Check the saving and adjust the quality if there is more to take.

Compressing JPEG XL: common questions

Is the file uploaded?
No. libjxl runs as WebAssembly inside your browser and the file stays on your device.
Can I open a JXL anywhere?
Not reliably. Safari displays it, Chrome does not, Firefox does not by default. Professional image software increasingly does. Treat it as a format for storage you control rather than for files you send to other people.
Is JXL better than AVIF?
At comparable file sizes the two are close, and JXL encodes several times faster. AVIF has the browser support, which for anything on a web page settles the question regardless of the technical comparison.

Sometimes the better answer is a different format — especially for a photograph stored as JXL.