BMP to transparent PNG
Free, no signup, and your image never leaves your device.
Open a BMP file, cut out the background, and save the result as a PNG with a real alpha channel.
| Source format | BMP |
|---|---|
| Transparency support | None |
| Compression | Lossless |
| Output format | PNG |
Why the output is a PNG
BMP simply has no way to record that a pixel is transparent. This is the single reason "make my BMP background transparent" always ends in a different file type — there is nowhere in a BMP to put the information.
How to do it
- Drop your BMP file onto the page, or paste it from the clipboard.
- The background is detected automatically; adjust the tolerance if anything is left behind.
- Use the eyedropper or the brush for anything the automatic pass missed.
- Choose PNG and download. The transparency is in the file, not faked with white.
Common questions
Can a BMP file have a transparent background?
No. BMP has no alpha channel at all, so transparency cannot be stored in it. Whatever you remove would come back as white or black. Saving as PNG is the only way to keep it.
Will the quality drop when I convert?
Not from the conversion. PNG is lossless, so the pixels it keeps are exactly the ones it was given. Any compression artefacts already in the BMP stay as they are — converting cannot undo them, but it does not add more.
Is my BMP file uploaded?
No. The browser decodes it locally and the processing runs on your own machine. There is no server in this, which also means no queue and no file size limit beyond what your device can hold.