Repack JPG photos as JPEG XL - about 20% smaller, not one pixel changed, and the original JPG can be restored bit for bit. Need a format Chrome shows? Use JPG to AVIF.
Need the JPG back later? JXL to JPG restores it.
JPEG XL can take an existing JPG and store the very same data more cleverly.
The result is about 20% smaller, shows exactly the same pixels and can be turned back into the original JPG, byte for byte.
That makes it ideal for photo archives and backups: a fifth of the disk space back, with zero risk.
| Lossless JPEG transcode | Re-encode from pixels | |
|---|---|---|
| Size | About 20% smaller | Smaller still at lower quality |
| Pixels | Identical | Re-compressed |
| Back to the exact JPG | Yes | No |
| Resize / options | Not used | Yes |
| Best for | Archives, backups | New, smaller copies |
Have PNGs? PNG to JXL stores them losslessly too. Test files are in the JPG sample files.
Drop your JPG files into the box, keep Lossless JPEG transcode on and press Convert to JPEG XL.
With Lossless JPEG transcode, yes - the pixels are identical and the original JPG can be rebuilt exactly. Re-encoding from pixels is lossy.
About 20% per photo with lossless transcode. Re-encoding at quality 75-90 can save 40-60%, but it is not reversible.
Yes, when the JXL was made with lossless transcode - djxl or JXL to JPG rebuilds the original file.
Safari 17+, Photoshop, Lightroom, GIMP, Affinity, darktable, and Windows 11 with the JPEG XL extension. Chrome and Firefox do not yet.
Yes, briefly - browsers cannot write JPEG XL. Files go over HTTPS to our server and are deleted the moment you download.
