Convert BMP images to lossless PNG locally - much smaller files, no upload, right in your browser.
Running locally on your device ...
0%
Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
BMP is an old, uncompressed Windows image format: pixel-exact but huge, because every pixel is stored in full. PNG stores the same pixels losslessly but compressed - usually a fraction of the size - and is opened by every program, browser and website.
The BMP is decoded locally and exported as PNG; any alpha channel is preserved. Nothing is uploaded - the conversion runs entirely in the browser.
BMP arose in the early days of Windows, when storage was budgeted generously and a simple, directly readable pixel store mattered more than small files. That very heritage makes BMP unwieldy today: its huge sizes get in the way when emailing or embedding on a website. PNG appeared in the late 1990s as a free, compressed successor and has been at home on every platform since - so you merely swap the uncompressed container for a modern, equally lossless format, with nothing changing about your pixels.
| Input formats | BMP |
|---|---|
| Output format | PNG |
| Batch processing | Yes |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: PNG is lossless - no detail is lost, but for photos the file stays larger than a JPG. Very large BMP can use a lot of memory on mobile devices.
No. The conversion runs entirely in the browser - even in airplane mode.
No, PNG is lossless. The pixels stay identical to the BMP.
Often much smaller, because BMP is uncompressed and PNG compresses losslessly - it varies a lot by content. As a rule of thumb: an uncompressed 24-bit BMP needs exactly 3 bytes per pixel, so a 4000x3000-pixel photo needs about 36 MB.
Yes, download individually or as a ZIP.