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JXL File Format (.jxl)

A JXL file stores an image under the JPEG XL coding system, a format built to losslessly repackage an existing JPEG into a smaller file or to encode a new photo at higher quality per byte than JPEG, WebP or AVIF.

.jxlImage Files

JXL at a glance#

Full nameJPEG XL (ISO/IEC 18181)
File extension.jxl
CategoryImage Files
DeveloperJoint Photographic Experts Group (JPEG committee), with Google and Cloudinary leading the reference implementation
First released2021
MIME typesimage/jxl
CompressionLossy or lossless, depending on how the file was written
SpecificationISO/IEC 18181 (JPEG XL Image Coding System)
FileFlip supportFileFlip reads and writes this format

What a .jxl file can hold#

These are the things a JXL file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.

Transparency (alpha channel)Yes
AnimationYes
LayersYes
Lossless compressionYes
Embedded metadataYes
Colour profilesYes
High dynamic rangeYes

Strengths and limitations of JXL#

What JXL does well

  • Can losslessly repack an existing JPEG into a JXL that's roughly 20% smaller, and reconstruct the original JPEG bit-for-bit afterward
  • Handles up to 32-bit sample precision for HDR and images as large as a terapixel
  • Progressive decoding shows a usable low-resolution preview before the full file arrives
  • Wide colour gamut and high bit depth support avoid the banding that 8-bit JPEG shows in skies and gradients

Where JXL falls short

  • Chrome and Firefox still keep JPEG XL decoding behind an experimental flag as of August 2026, with default support slated for September 2026
  • Safari 17 and later is currently the only major browser that renders it without any setup change
  • Most photo editors outside Adobe's latest releases, Krita, GIMP 3.0+ and the Affinity suite still can't open it
  • Because default browser support hasn't shipped yet, a JXL used directly on a website today needs a fallback image

Use JPEG XL for archiving and photo libraries where you want smaller files than JPEG without giving up the option to reconstruct the original JPEG exactly, especially once Chrome and Firefox finish rolling out default decoding.

Convert JXL to JPEG or PNG for anything going on the web today, since most browsers still require a manual flag to display JPEG XL directly.

How to open a .jxl file#

A .jxl file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts JXL into a format your machine already opens, and it does it in the browser tab rather than on a server.

PlatformPrograms that open it
WindowsPhotos (Windows 11 24H2+), GIMP, IrfanView, XnView MP, ImageMagick
macOSPreview (macOS Sonoma+), Adobe Photoshop (26.8+), Affinity Photo, GIMP
LinuxGIMP, ImageMagick, libjxl tools
iOSPhotos (iOS 17+)
WebFileFlip

JXL questions people ask#

What is a JXL file?

A JXL file is an image encoded with JPEG XL, a format from the JPEG standards committee designed either to losslessly shrink an existing JPEG or to encode new photos at better quality per byte than JPEG, WebP or AVIF. It became an ISO standard starting in 2021.

Do browsers support JPEG XL yet?

Safari has supported JPEG XL natively since version 17. Chrome and Firefox restored decoding support during 2025 and 2026 but keep it behind an experimental flag as of August 2026, with both browsers targeting default support around September 2026.

Why did Chrome remove JPEG XL support?

Chrome shipped an experimental JPEG XL decoder starting in 2021 but removed it in version 110, released December 2022, citing limited ecosystem interest at the time. Chrome brought decoding back behind a flag starting with version 145 in early 2026 as adoption grew.

Can I convert a JPEG to JXL without losing quality?

Yes. JPEG XL has a lossless transcoding mode built specifically to repackage an existing JPEG's data into a smaller JXL file, and the process can be reversed to get back the exact original JPEG bytes. This is different from lossy JXL encoding, which re-compresses the image and is not reversible.

What opens JXL files right now?

On macOS, Preview and Photos read JXL natively since Sonoma. On Windows and Linux, GIMP 3.0 and later, ImageMagick, IrfanView and XnView MP all open it, and recent Photoshop and Affinity releases support it too. Most web browsers still need a manual flag enabled, or the file converted to JPEG or PNG for immediate use online.

Converting JXL files#

Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.