Convert BMP and bitmap images to lossless PNG directly in your browser. Keeps every pixel exact with transparency preserved where present.
Last updated: August 2026
Lossless
Quality
Full
Transparency
Batch
Multiple Files
Private
No Uploads
Drop BMP files here or click to browse
Supports .bmp and .dib, all processing stays in your browser
Drop or select your BMP file
One file or many, .bmp or .dib. Nothing is uploaded.
Conversion starts automatically
Decodes and re-encodes as lossless PNG the moment it's added.
Download your PNG
One file downloads directly, two or more can download together as a ZIP.
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.
Converting a photo to PNG when JPEG would be smaller
PNG's lossless encoding is great for transparency, text and line art, but for a photographic BMP it often shrinks the file far less than JPEG would, and can occasionally end up larger than a high-quality JPEG of the same image.
Assuming every 32-bit BMP has real transparency
The 32-bit BMP format reserves a byte per pixel for alpha, but not every program that writes 32-bit BMPs stores genuine transparency there. If the output PNG looks fully opaque, the source BMP likely never had real alpha data despite the format supporting it.
Trying to drop a non-BMP file
This tool only accepts .bmp and .dib files. Other formats need a different converter on this site first.
Looking for a quality slider
There isn't one for PNG output, it's always lossless. If you want to trade quality for a smaller file, convert to JPEG or WebP instead.
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. Photographic content compresses less dramatically since PNG's compression relies on repetition that photos rarely have much of.
Some BMP files include an alpha channel for transparency, most commonly in 32-bit BMP files. When the source file has genuine alpha data, this tool preserves it through the conversion so transparent areas remain transparent in the output PNG. Not every 32-bit BMP actually carries real transparency data though, some programs pad that extra byte with zeros rather than a meaningful alpha mask, in which case there's nothing real to preserve.
No. PNG is always lossless, so there's no quality slider to configure, unlike the JPEG or WebP converters on this site. The output is always a pixel-perfect match of what the BMP decoded to.
BMP files virtually never carry EXIF metadata in the first place, it isn't a format feature BMP typically supports the way JPEG does. So there's generally nothing to strip. The conversion still decodes to raw pixels and re-encodes as PNG, so even in the rare case extra data was embedded, it would not carry over.
Yes. Drop or select several BMP files and each converts independently. With a single finished file, the download button saves it directly. Once two or more files finish, you get the option to download them all together as one ZIP archive.
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.
No sign-up. No upload to server. Drop your BMP file above and download the PNG in seconds.
