Convert and compress PNG, JPEG, WebP and GIF files to JPEG XL from the Explorer. Offline; nothing leaves your machine.
JPEG XL (.jxl) is a modern image format. Chrome and Firefox show it by default since October 2026, and Safari since 17.
It is good for three things today:
JPEGs, lossless. About 20% smaller, and the original JPEG comes back byte for byte.
Screenshots and graphics, exact. Every pixel kept, 86 to 93% smaller than the PNG.
Photographs, by look. One quality number, 1 to 100.
Built on rapier-jxl, an MIT-licensed JPEG XL encoder in WebAssembly.
Commands
Convert to JPEG XL: right-click files or a folder in the Explorer. name.jxl is written beside each file.
Existing files are never replaced. Every new file is decoded and compared with its original first: a file that
fails the check is not written, and the message says why. Where an editor cannot run the check, the file is written
and the message says it was not checked.
Compare with Original: the picture and its .jxl side by side or with a slider, with both sizes.
Convert JPEG XL Back: to PNG, or to the original JPEG where the file came from one.
Opening a .jxl file shows the picture, its size and its dimensions.
Settings
Setting
Default
jxl.quality
90
How the picture looks, 1 to 100. Not a bit rate.
jxl.exact
auto
auto keeps screenshots and graphics exact and uses quality for photographs.
jxl.effort
7
1 is fastest, 9 is smallest.
jxl.reencodeJpeg
off
Re-encode JPEGs at the quality above instead of recompressing them losslessly.
jxl.trashOriginal
off
Move each original to the trash once its .jxl is written and checked. With no trash (VS Code for the Web), it stays.
Privacy
No network calls, no telemetry, no remote content. Works offline, in VS Code and on vscode.dev.
