About this tool
BMP files from scanners, old games, and legacy Windows apps are huge because they are uncompressed. PNG stores exactly the same pixels at a fraction of the size, and opens on every modern device.
About the formats: BMP is Windows' original uncompressed bitmap format. Files are enormous and it has no transparency support, so it survives mainly in legacy software, scanners, and old game assets. PNG (Portable Network Graphics) is a lossless image format with full transparency support. It is the standard choice for screenshots, logos, icons, and anything with sharp edges or text, but it produces much larger files than JPG or WebP for photographs.
BMP and PNG, side by side
| .bmp in | .png out | |
|---|---|---|
| Compression | None, usually | Lossless |
| Transparency | No in practice | Yes |
| Animation | No | No (APNG aside) |
| Opens on | Everything | Everything |
Rows where the two differ are marked. The full story on each: BMP files and PNG files.
How to use it
- Drop your BMP files into the box above, or click to browse. Nothing is uploaded.
- Click Convert to PNG and wait a moment.
- Download the results individually or all at once as a ZIP.
Questions
Is BMP to PNG lossless?
Completely. PNG compression is lossless, so the image is pixel-for-pixel identical.
How much smaller will the PNG be?
Typically 50-90% smaller, depending on how much flat color the image contains.
Is it free, are files uploaded, which browsers work: the general questions are answered once for the whole site.