BMP to PNG
Shrink bitmaps into lossless PNG files.
Drop BMP images here, or click to browse
Several files at once, up to 25 MB each. Converted to PNG in your browser — nothing is uploaded.
PNG options
PNG is lossless: pixels and transparency are kept exactly.
BMP to PNG Converter
Convert Windows bitmaps into PNG images without quality loss. Drop one or many .bmp files, and the converter decodes them with your browser and re-encodes them as PNG — the modern lossless format every website, phone, and editor understands. Files are processed locally and never uploaded.
Why PNG is the natural replacement for BMP
BMP stores pixels raw. That made sense in the 1980s when decoding speed mattered more than disk space, but today it mostly wastes storage and bandwidth. PNG keeps exactly the same pixels and compresses them with DEFLATE plus per-row prediction filters. Screenshots, diagrams, and UI graphics — the most common BMP content — shrink dramatically because they contain large areas of identical color.
| BMP | PNG | |
|---|---|---|
| Compression | None (RLE rarely used) | Lossless DEFLATE |
| Transparency | 32-bit only, poorly supported | Full alpha channel |
| Web support | Partial, not recommended | Universal |
| Typical screenshot size | 6 MB | 300 KB |
Common reasons to convert
- Old screenshots and scans saved by Windows Paint or scanner software.
- Publishing images online, where BMP is often rejected or shown as a download.
- Archiving: PNG saves disk space while staying lossless.
- Sharing in chat or email without hitting attachment limits.
What to expect
Dimensions and colors stay identical. Bitmaps with a palette (8-bit or less) are expanded to full color by the browser, and the PNG encoder compresses them efficiently again. Resolution metadata (DPI) is not carried over, which only matters for print workflows. If you need an even smaller file and can accept slight loss, try BMP to JPG.
Frequently Asked Questions
Will I lose quality converting BMP to PNG?
No. Both formats are lossless, so every pixel is kept exactly. PNG just compresses the data, often making the file 5–20 times smaller.
Which BMP variants can be converted?
Anything your browser can decode: 1, 4, 8, 16, 24, and 32-bit bitmaps, RLE-compressed bitmaps, and top-down or bottom-up row order. Chrome, Edge, Firefox, and Safari all ship a BMP decoder.
Is the alpha channel of a 32-bit BMP preserved?
Yes, when the bitmap declares an alpha mask (BITMAPV4/V5 headers), the browser reads the transparency and the PNG keeps it. Many 32-bit BMPs from older programs leave the alpha byte unused; those come out opaque.