Free tools › Images
PNG to JXL
The image format that beats JPG, PNG and WebP at once — made from any of them.
More free conversions, where you upload. The Fylane extension does the same work inside any upload form, on its own free share every day.Add to Chrome
How to convert PNG to JXL
- Drop the image.
- Pick lossless or a quality.
- Press Convert and download the JXL.
What happens to your file
The picture is decoded to a lossless PNG and libjxl’s cjxl encodes it — lossless at 100, or at your quality — at a middle effort setting, because the slowest one is minutes on a large photo for a few per cent. Transparency is kept.
Few apps read JPEG XL today (Safari does). Keep the original until the places you share to accept it.
Questions
Is lossless really lossless?
Yes — JPEG XL at quality 100 reproduces every pixel exactly, and the file is usually smaller than the PNG it came from. That is the headline reason to use it: strictly less data for strictly identical pixels.
How much smaller than PNG should I expect?
For photographs, often a lot — JPEG XL was designed for them and PNG was not. For flat-colour graphics, logos and screenshots, PNG is already efficient and the saving is modest. Try one of each before converting a library.
What actually supports JPEG XL?
This is the catch. Safari reads it, and so do several image editors and viewers. Chrome removed support and has not restored it, which means a JXL on a public web page will not display for most visitors. Keep the original until the places you publish to accept it.
Should I use JXL or WebP or AVIF?
For anything going on the open web today, WebP or AVIF, because browsers read them. JPEG XL is the better format on the merits and the worse one in practice — worth using for archives and personal libraries where you control the reader.
Does transparency survive?
Yes. The alpha channel is preserved, lossless or lossy.
Why not the slowest encoder setting?
Because it costs minutes on a large photograph and buys a few per cent. The middle effort setting is where the trade stops being worth it.
Do it once, not on every form
A form that wants a square JPEG under 240 KB says so on the page. The Fylane extension reads that, fits your photo to it, and puts it in the field — without you working out what 240 KB looks like.
And it keeps the result. The next application that asks for a résumé, a cover letter and a photo fills all three from one tap, each one refitted to what that site accepts.
Your files stay in the browser, encrypted, on your machine. Nothing is uploaded to keep them and nothing is sent anywhere to fill a form.
Related tools
Do this in code
curl -X POST https://api.fylane.dev/v1/jobs \
-H "Authorization: Bearer $FYLANE_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"file_id": "<file id>",
"operation": "image.convert",
"options": {
"format": "jxl",
"quality": 90
}
}'The same operation, image.convert — Re-encode to WebP, JPEG, PNG or AVIF at your quality. Upload first with the quickstart; every option is on the operations page. 500 free credits a month, then $5 per thousand.