Convert BMP and bitmap images to lossless PNG directly in your browser. Keeps every pixel exact with transparency preserved where present.
Lossless
Quality
Full
Transparency
Instant
Conversion
Private
No Uploads
Drop BMP files here or click to browse
Supports .bmp and .dib, all processing stays in your browser
PNG is the right choice whenever the conversion needs to be completely lossless, or when the BMP contains transparency.
Icons and graphics with transparency
32-bit BMP files sometimes carry an alpha channel that PNG handles natively, unlike JPEG.
Diagrams and screenshots with text
Text and line art compress better and stay crisper in PNG than in JPEG, which can blur sharp edges.
Images that need further editing
Keeping a lossless PNG avoids compounding quality loss across multiple edit and re-save cycles.
Smaller files without quality loss
PNG compression alone often shrinks an uncompressed BMP significantly while keeping the image identical.
PNG's lossless compression works by finding repetition, flat areas of identical color, sharp edges, the same pattern repeated across a screenshot or icon. That's why a BMP full of graphics or text can shrink by half or more once converted. A photographic BMP behaves very differently, since natural photos are full of subtle noise and gradients with almost no exact repetition, so the same conversion might only trim 10 or 15 percent, occasionally landing larger than the same photo saved as a high quality JPEG.
Before committing to PNG, think about what's in the BMP. A scanned photo, a picture of a person, or anything with sky, skin tones or natural texture will almost always end up smaller and just as usable as a JPEG or WebP through BMP to JPG or BMP to WebP. Save PNG for screenshots, icons, diagrams and anything with flat color or text.
The BMP format reserves a fourth byte per pixel in its 32-bit variant for an alpha channel, but not every program that writes 32-bit BMPs actually stores real transparency data there. Some just pad that byte with zeros or leftover values instead of a genuine alpha mask. This tool preserves whatever is actually present in the file, so if the resulting PNG looks fully opaque or oddly transparent, the original BMP likely never carried real alpha information despite its 32-bit format.
PNG compresses by predicting each pixel from its neighbors before applying its main compression pass, a step that pays off enormously on flat regions where neighboring pixels often match exactly. Icons, UI screenshots and line art hit that sweet spot consistently, which is why they're the clearest win for a lossless format like PNG over anything lossy.
PNG is a lossless format, so converting from BMP to PNG keeps every pixel exact with no quality loss, unlike JPEG which uses lossy compression. PNG is the right choice when the BMP contains transparency, sharp edges, text or line art, or when the image needs to remain pixel-perfect for further editing.
In almost every case, yes. BMP files are typically stored uncompressed, while PNG uses lossless compression that can reduce file size significantly, often by 50 percent or more, especially for images with large areas of flat color, text or simple graphics.
Some BMP files include an alpha channel for transparency, most commonly in 32-bit BMP files. When present, this tool preserves the alpha channel through the conversion, so transparent areas in the source BMP remain transparent in the output PNG.
No. Both the decoding and the PNG encoding happen entirely in your browser. Your file never leaves your device at any point during the conversion.
