What is JXL (JPEG XL)?
Complete guide to the JXL file format
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What is JXL (JPEG XL)?
JPEG XL is a next-generation image format designed to be the eventual successor to JPEG. It offers significantly better compression than JPEG while maintaining backward compatibility and supporting modern features.
JXL can losslessly recompress existing JPEG files to about 80% of their original size, and for new images it offers 60% better compression than JPEG at equivalent quality.
How JPEG XL Works
JPEG XL combines two technical lineages: a VarDCT mode derived from Google's PIK for photographic images, and a modular mode derived from Cloudinary's FUIF for lossless and non-photographic content.[5] It supports very high bit depths, wide color gamuts, HDR, animation, transparency, and progressive decoding, and a single codestream can encode images up to one billion pixels per side.[3] Crucially, it can losslessly transcode an existing JPEG into the JXL format and reconstruct the original bitstream, easing migration from the legacy format.[5]
Standardization
JPEG XL was developed by the JPEG Committee (ISO/IEC JTC 1/SC 29/WG 1); its core coding system is standardized as ISO/IEC 18181-1 and the file format as ISO/IEC 18181-2, with the 2024 editions consolidating earlier amendments.[1][2] The reference encoder and decoder are distributed as the open-source libjxl library.[3]
Adoption Challenges
Despite its technical advantages, browser support has been uneven: Google removed JPEG XL from Chrome in 2023, while Apple added support in Safari, leaving the format without the universal reach that would let it fully replace JPEG.[5] The Library of Congress nonetheless tracks JXL as an emerging format with strong preservation potential.[4]
Technical Details
JXL vs Other Image Formats
| Feature | JXL | JPG | WebP | AVIF |
|---|---|---|---|---|
| Type | Raster | Raster | Raster | Raster |
| Compression | Lossy & lossless[3] | Lossy | Lossy & lossless | Lossy & lossless |
| Transparency | Yes[5] | No | Yes | Yes |
| Animation | Yes[5] | No | Yes | Yes |
| Standardized by | ISO/IEC (JPEG XL)[1] | ISO/IEC, ITU-T | AOMedia | |
| Browser support | Limited/partial | Universal | Broad | Broad |
JXL offers efficient lossy and lossless compression plus lossless JPEG transcoding, but browser adoption still trails WebP and AVIF.
Pros and Cons
Advantages
60% better compression than JPEG for equivalent quality images.
Can losslessly transcode existing JPEGs to JXL reducing size by ~20%.
HDR, wide color gamut, animation, and transparency in one format.
JXL lossless mode outperforms PNG for photographs.
Disadvantages
Chrome removed JXL support in 2022. Firefox has support behind a flag. Only Safari 17 supports it natively.
JXL encoding at maximum compression is very slow compared to JPEG or WebP.
Most image editors and tools do not yet support JXL format.
Lack of Chrome support has significantly slowed JXL adoption.
When to Use JXL (JPEG XL)
Here are the most common situations where JXL (JPEG XL) is the right choice:
Future Web Images
JXL may become the standard web image format once browser support improves.
JPEG Archiving
Use JXL for losslessly recompressing JPEG archives to save storage space.
HDR Photography
JXL is excellent for HDR photography distribution once support improves.
Print Quality Images
JXL's lossless mode is excellent for print-quality image archiving.
Convert JXL (JPEG XL) Files
Need to convert your JXL files? Use our free online converter.
Try Image Converter FreeFrequently Asked Questions about JXL (JPEG XL)
Is JPEG XL better than AVIF?
JXL generally achieves better compression and has more features than AVIF, but AVIF has much better browser support currently.
Does Chrome support JPEG XL?
Chrome removed JXL support in 2022. Safari 17+ supports JXL. Firefox has experimental support.
Should I use JXL for my website?
Not yet - browser support is too limited. Use AVIF or WebP with JPEG fallback for production websites.
What software opens JXL?
GIMP 2.10+, Darktable, and some specialized tools support JXL. Most mainstream editors do not yet.
When will JXL be widely supported?
Browser support timelines are uncertain. AVIF is currently the better choice for modern web images.