Convert BMP to PNG
BMP stores pixels raw, so a plain screenshot can weigh several megabytes. PNG stores the same pixels compressed. Drop your bitmaps here and get PNGs that look identical and are a fraction of the size — converted in your browser, nothing uploaded.
Drop BMP files here
Multiple files allowed
Why the saving is so large
An uncompressed 24-bit BMP spends three bytes per pixel no matter what the picture looks like: 1920×1080 costs about 5.9 MB whether it's a photo or a blank white rectangle. PNG applies lossless DEFLATE compression plus row filtering, which is devastatingly effective on the flat colours and repeated runs that dominate screenshots, diagrams and UI captures. Nothing is thrown away — the decoded pixels are byte-identical.
Need to go the other way for a legacy tool that only reads bitmaps? PNG to BMP writes real 24-bit and 32-bit BMP files.
FAQ
Is any quality lost?
None. Both formats are lossless, so the pixels in the PNG are exactly the pixels in the BMP.
What about 32-bit BMPs with an alpha channel?
Transparency comes through when the browser's BMP decoder recognises it — which depends on which BMP header variant the file uses. Older BI_RGB 32-bit bitmaps often report their fourth byte as padding, so those flatten to opaque.
Can it handle RLE-compressed or 16-bit BMPs?
Usually yes — decoding is your browser's job here, and browser BMP support covers the common 8/16/24/32-bit variants. A file that fails to load is one the decoder rejected.
Can I shrink the result further?
Yes — run the PNG through Compress for a lossy re-encode, or Reduce colors if it's a screenshot or diagram with a limited palette.