JPEG XL to JPG
Nothing you choose here leaves your browser. There is no server to send it to — the conversion happens on your own device, using the codecs your browser already has, and nothing is uploaded, stored or seen by anyone.
What this conversion costs you
Out of the format almost nothing reads. JPEG XL is the better format on nearly every measure and is read by hardly anything, which is the whole reason this conversion exists. No browser reads it either, so this page has to fetch a decoder before it can tell you anything about your file at all — including how big it is.
Transparency. JPG has no alpha channel. Anything transparent is painted onto a background colour you choose below.
Some detail, permanently. JPG is lossy. The quality setting decides how much goes, and it cannot be put back by converting again.
The metadata. Going through a canvas drops EXIF, so the camera, the date and any GPS coordinates do not survive. That is a side effect rather than a feature, and a useful one.
How it works, and why nothing is uploaded
Your browser can already read JPEG XL and write JPG; every operating system ships those codecs and has for years. So this page asks the browser to do the work rather than shipping a copy of a codec to do it here. That is why there is nothing to upload, nothing to wait for and no queue — and why the file cannot be seen by anyone, because it is never sent.
It also means the page can tell you when your browser cannot do it, which it will say plainly rather than producing a broken file. The one thing it will never do is hand you a file with the wrong contents: browsers quietly return a PNG when asked for a format they cannot write, so every conversion here checks what came back and refuses if it is not what was asked for.
Where to go next
The same conversion, the other way round, and the other targets:
- JPG to JPEG XL — the same conversion the other way
- JPEG XL to PNG — lossless, with real transparency, and the safe choice for anything with text or sharp edges
- JPEG XL to WebP — Google's format, usually a good deal smaller than JPG or PNG at the same quality
- HEIC converter — iPhone photographs, which need a different approach
What this does not do
It converts one picture at a time from each file, and does not edit, crop or retouch. It cannot convert a format your browser cannot read — JPEG XL, QOI and HEIC all need something extra, and HEIC has a page of its own.
It does not upload anything, so it cannot work on a file that is not on the device you are using. And it does not preserve metadata: if you need the EXIF kept, this is the wrong tool, and if you wanted it gone, this is a convenient way to do it.