BMP to PNG Converter — Free, In-Browser

The conversion with zero trade-offs

Converting BMP to PNG is the rare format conversion where you gain everything and lose nothing. A PNG file stores the exact same pixel values as the BMP—every bit identical—yet the file shrinks dramatically. There is no quality slider on this tool, and there is none precisely because there is no quality decision to make.

Why BMP files are so enormous

A 24-bit BMP file stores three raw bytes for every pixel: one each for red, green, and blue. No compression, no clever encoding. A 1920×1080 image contains 2,073,600 pixels. Multiply that by 3 bytes: you get 6,220,800 bytes—roughly 6 megabytes—whether the image is a detailed photograph or a completely blank white rectangle. BMP applies almost no compression worth the name. This is why most images on your computer are smaller: they use formats like PNG or JPG.

PNG compresses losslessly and preserves every pixel

PNG stores the exact same pixel values as the BMP but compresses them losslessly using an algorithm that recognizes patterns: large blocks of the same colour, repeated sequences. Nothing is approximated or discarded. Every pixel comes out bit-for-bit identical to the original. The savings are large and depend on content—images with flat colour regions (screenshots, diagrams, logos) compress far more than complex photographs. This is the opposite of converting to JPG, where you always sacrifice quality for file size.

What you can and cannot do here

This tool converts BMP to PNG perfectly. You can optionally resize down (which is lossy, so it is off by default). PNG cannot make an image better than the BMP was—it only stores what is there. Very large BMPs are decoded in your browser, so enormous files are limited by available device memory. For typical images, conversion is lossless, instant, and completely private. See our image optimizer if you need additional fine-tuning.