Convert JPG to JXL

JPEG XL has a unique feature: it can recompress an existing JPEG file losslessly, producing a ~20% smaller file from which the original JPEG can be perfectly reconstructed, bit-for-bit. No other format offers this.

For lossy encoding at equivalent visual quality, JXL is roughly 60% smaller than legacy JPEG. For lossless JPEG recompression, the savings are about 20%.

Safari 17+ supports JXL natively. For other browsers, FastEdit can decode JXL files via WebAssembly regardless of native browser support. Native support in Chrome and Firefox is expected to expand over time.

If you use lossless JPEG recompression, there is no risk: you save ~20% storage and can perfectly reconstruct the originals. For lossy re-encoding, keep the originals as a backup since the process is not reversible.