Convert BMP to PNG
Drop your BMP bitmap files and download lossless PNG copies that are usually a fraction of the size. The conversion runs entirely in your browser, so even old scans and screenshots never reach a server.
How to convert BMP to PNG
- Drop your BMP files into the box below.
- The browser decodes each bitmap and a Canvas re-encodes it as a lossless PNG.
- Download the PNG copies individually or as a batch.
Why convert BMP to PNG?
BMP is an old Windows bitmap format that stores pixels almost completely uncompressed, which makes files enormous — a single full-screen BMP can be several megabytes for an image a PNG would store in a few hundred kilobytes. Because both BMP and PNG are lossless, converting from BMP to PNG throws away none of the image quality; it simply applies efficient lossless compression and adds proper transparency support. PNG is also far more widely accepted than BMP on the modern web: most upload forms, content systems, chat apps and design tools handle PNG natively but balk at BMP. Convert BMP to PNG whenever you have legacy bitmaps from old software, Windows screenshots saved as BMP, or scanner output, and you want a smaller file that still keeps every pixel intact and uploads anywhere.
How we compare
The closest peer to this tool is Google's Squoosh, which also runs fully in your browser. Squoosh focuses on compression for the modern web and does not handle HEIC or batch conversion. Cloudconvert and Convertio cover more formats but upload your files to their servers and meter usage.
| This site | Squoosh | Cloudconvert | Convertio | |
|---|---|---|---|---|
| Files stay on your device | ||||
| No signup | Limited | Limited | ||
| No ads | ||||
| Batch conversion | ||||
| Supports HEIC | ||||
| Works offline |
Frequently asked questions
Will I lose any quality?+
No. Both BMP and PNG are lossless, so the PNG is pixel-for-pixel identical to the source bitmap — just much smaller thanks to PNG's compression.
How much smaller will the PNG be?+
Often 70–95% smaller, because BMP stores pixels almost uncompressed while PNG applies lossless DEFLATE compression.
Are my files uploaded?+
No. Decoding and PNG encoding both happen inside your browser tab.
Does it preserve transparency?+
If the BMP carries an alpha channel it is preserved; most BMP files are fully opaque and convert to an opaque PNG.
What is the maximum file size?+
Limited only by your browser's memory. Large bitmaps use more RAM during decoding but are otherwise fine on desktop.
Which browsers are supported?+
Every modern browser — Chrome, Edge, Safari, Firefox, Opera and Brave.
Related converters
Files processed in your browser. We never see them.