BMP to PNG Converter

BMP is an uncompressed (or minimally compressed) bitmap format, which makes files unusually large for what they contain. Converting BMP to PNG shrinks the file, often dramatically, while keeping every pixel exactly as it was, PNG's compression is lossless, so unlike converting to JPG, nothing about the image itself is discarded. This is one of the rare conversions on this site that's a straightforward size win with no quality trade-off: BMP had no compression to lose in the first place. This tool converts BMP to PNG directly in your browser, no software to install and no file uploaded to a server.

How to use

1. Upload your BMP. Drag a BMP file onto the drop zone or click to browse. Only BMP files are accepted for this converter.
2. Click Convert to PNG. There's no quality slider to set, PNG encoding is lossless, so there's no quality trade-off to choose. Any transparency in your BMP is preserved.
3. Download your PNG. Click Save to download the converted file, or Save As to pick the filename and location yourself.

BMP vs PNG

BMP stores image data uncompressed, or with only basic lossless compression in some variants, resulting in files that are far larger than necessary for the amount of visual information they contain. PNG uses genuinely efficient lossless compression, it keeps every pixel exactly as encoded, the same guarantee BMP offers, but in dramatically less space. Converting BMP to PNG is unusual among format conversions in that it's essentially a pure win: no image data is discarded either way, so you get a meaningfully smaller file with zero quality trade-off, unlike converting a lossless source to a lossy format like JPG or a quality-adjustable WebP.

Tips for best results

• This conversion has no quality trade-off. Both BMP and PNG are lossless, so converting between them doesn't discard any image data, you're only changing how the same pixels are stored, and PNG stores them far more efficiently.
• Expect a significant size reduction. BMP files are frequently many times larger than a PNG of the same image, since BMP applies little to no compression. Converting is usually the simplest fix for an oversized BMP.
• Transparency is preserved if present. Some 32-bit BMP files include an alpha channel. If yours does, that transparency carries over cleanly to the PNG, both formats support it.
• Use PNG if you'll edit the image further. Since this conversion is already lossless, the resulting PNG is a safe, space-efficient master copy for further edits, better than keeping the oversized original BMP around.

Why use PixMidas

• 100% private. The conversion redraws your image on a canvas and re-encodes it entirely in your browser. Your BMP is never uploaded to any server.
• A genuinely lossless upgrade. Unlike most format conversions on this site, BMP to PNG has no honesty caveat about lost quality, both formats are lossless, so you only gain a smaller file.
• No account needed. Free and instant. Works in any modern browser, no installation required.

Frequently asked questions

Does converting BMP to PNG lose any image quality?

No. Both BMP and PNG are lossless formats, PNG's compression doesn't discard any pixel data, it just stores the same information more efficiently. This is one of the few conversions here where there's no quality trade-off at all.

How much smaller will the PNG be?

Usually substantially smaller, often by a large factor, since BMP typically applies little to no compression while PNG's lossless compression is genuinely space-efficient. The exact reduction depends on the image content, photos with lots of detail compress less than simple graphics with flat colors.

Why is my BMP file so large in the first place?

BMP stores image data uncompressed, or with only very basic lossless compression in some variants, so its file size scales directly with pixel dimensions and color depth rather than actual visual complexity. A modest-sized photo can easily be tens of megabytes as a BMP.

Does my BMP's transparency carry over?

Yes, if it has any. Most BMP files don't include an alpha channel at all, but some 32-bit BMP variants do, and PNG fully supports transparency, so any alpha channel your BMP has will be preserved in the converted PNG.

Why would I keep a BMP instead of always using PNG?

In practice, you usually wouldn't. BMP mostly persists because certain screen capture tools, older software, and some technical or industrial equipment still produce it by default, not because it offers any advantage over PNG for storage or sharing. Converting to PNG is typically a strict improvement for file size with no downside.

Is my image uploaded to a server?

No. The entire conversion runs on your device using your browser's Canvas API. Your BMP is read locally, redrawn, and re-encoded as PNG without ever being sent anywhere.