Free BMP to PNG Converter
You have a BMP file that is far too large and you need to shrink it without losing any quality. JPG would compress it more aggressively but introduce lossy artifacts. You need a free BMP to PNG converter that applies lossless compression while keeping every pixel intact.
Drop your BMP below. OnlyFiles converts it to PNG entirely in your browser. Your file never leaves your device. No upload, no account, no watermark, no daily limit. The output is a lossless PNG that preserves every detail of the original.
This free BMP to PNG converter is the right choice when quality matters more than file size.
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Why convert BMP to PNG instead of JPG
BMP is uncompressed. PNG is lossless compressed. JPG is lossy compressed. The choice between PNG and JPG depends on what you need.
Convert to PNG when you need to preserve every pixel exactly as it exists in the BMP. PNG applies lossless compression, meaning the image quality is identical to the original. File sizes typically drop by 50 to 70% compared to BMP. This is the right choice for screenshots, diagrams, text-heavy images, logos, and any graphic where sharp edges matter.
Convert to JPG when file size is your priority and you can accept a small quality reduction. JPG achieves 90 to 95% size reduction from BMP. Use JPG for photographs and images where slight compression artifacts are invisible.
How the free BMP to PNG conversion works
The conversion uses the Canvas API in your browser. Your BMP file is loaded into a canvas element at its original dimensions and exported as a lossless PNG file.
PNG compression works by finding patterns in the pixel data and encoding them efficiently. Unlike JPG, it does not discard any information. The output PNG is visually and mathematically identical to the original BMP, just stored in less space.
The process runs entirely in JavaScript on your device. No server contact. No data leaves your browser.
How much smaller will the PNG be
The reduction depends on image content. For screenshots and graphics with large areas of solid color, expect a 60 to 80% reduction. A 10 MB BMP screenshot might compress to a 2 to 3 MB PNG.
For photographs with complex color variations, the reduction is smaller, typically 30 to 50%. PNG compression is less effective on photographic content because there are fewer repeating patterns. If your BMP is a photograph and file size is the priority, consider converting to JPG instead.
Common questions about free BMP to PNG conversion
Is converting BMP to PNG truly lossless?
Yes. PNG uses lossless compression. The output image is pixel-for-pixel identical to the original BMP. No data is lost or modified during conversion.
When should I choose BMP to PNG over BMP to JPG?
Choose PNG when quality preservation matters. Screenshots, text, logos, diagrams, medical images, and any content with sharp edges should be PNG. Choose JPG when you need the smallest possible file and the content is photographic.
Why not just keep the BMP?
BMP files are unnecessarily large because they apply no compression at all. PNG gives you the same quality in a smaller file that is accepted by every modern application. There is no reason to keep BMP unless legacy software requires it.