Converting BMP to JPEG XL gives you a much smaller file. It runs in your browser: nothing is uploaded, there is no queue and no size limit.
What changes when you convert BMP to JPEG XL
- BMP is lossless and JPEG XL is not. Expect a much smaller file and a very small, usually invisible, loss of detail. Keep the BMP if you may edit again.
When to convert, and when not to
Convert to JPEG XL for archiving photos without quality loss. Can recompress a JPG losslessly and shrink it by ~20%. Excellent quality, limited browser support.
Keep BMP for legacy Windows software. Uncompressed Windows bitmap. Huge files, trivially simple.
How to convert BMP to JPEG XL
- Drop your BMP file on the converter above, or click to choose. Several at once is fine.
- Check the options if you need them: quality, resize, width (px), height (px), with both set, scale (%), never enlarge beyond the original.
- Click Convert, then Download. Nothing was sent anywhere, your browser did the work.
Questions
Is my BMP file uploaded?
No. The conversion runs in your browser with WebAssembly. There is no upload endpoint on this site. You can open your browser's Network tab, or go offline after the page loads, and it still works.
Is there a file size limit?
No fixed one. The limit is your device's memory: a large images file on a phone is slower than on a laptop, but nothing is rejected for being big.
Is it free?
Yes, without an account, without a daily cap and without a watermark. Your device does the computing, so there is no server bill to pass on.
Will the quality drop?
JPEG XL is lossy, so a little detail is traded for a smaller file. At quality 85 the difference is invisible on photos. For graphics with sharp edges, prefer a lossless format such as PNG.
Can I convert several files at once?
Yes. Drop them all; each is converted in turn and you can download them one by one or as a single ZIP.
Which engine does the conversion?
Image engine (jSquash: mozjpeg, oxipng, libwebp, libavif, libjxl), compiled to WebAssembly and running in your browser, on all your CPU cores when the browser allows it. First use downloads about 1.5 MB, cached afterwards.