Convert BMP to PNG

How to use the BMP to PNG converter

1. Choose the BMP images, or drop the folder holding them.
2. Leave the size alone, or scale it under More settings.
3. Convert and download the PNGs or one ZIP of all of them.

Lossless, yet much lighter

PNG predicts each row of pixels from the one above and then deflates the result, the same compression family ZIP uses. Captures with flat areas and sharp text routinely drop by 80 percent or more; grainy photographs shrink less, because natural detail is hard to compress without losing anything.

After encoding, OxiPNG searches for a tighter way to store the data. When a bitmap uses 256 colours or fewer, as many 8-bit BMPs do, it is saved as a palette PNG automatically.

Good fits for PNG

Game sprites, sprite sheets and retro pixel art keep their hard edges and exact palette colours, and PNG opens in every engine and editor. Software screenshots stay readable for tutorials, bug reports and on-screen overlays.

For camera photos where a small file matters more than a perfect copy, a JPG will be several times smaller still.

Output from older equipment

Machine controllers, measuring instruments and long-retired Windows programs often save nothing but BMP. As PNG, their graphs, readings and screen text become light enough to attach to a ticket or report without blurring a single digit.

Output files reuse the original names with a .png ending, so a numbered series of captures stays in order. Drop a whole folder and the ZIP button gathers every result.

Questions