BMP to PNG Converter
Convert BMP bitmap images to PNG with no loss of quality. Files stay on your device.
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Best under 50MB / 50 files
Related Image Tools
This BMP to PNG converter turns Windows bitmap files into PNG without changing a single pixel. BMP is an old format that stores a picture with no compression, so the files are large and many websites and apps will not accept them. PNG holds exactly the same picture in less space and opens everywhere. Add your .bmp files and each is converted at once in your browser.
How to Convert BMP to PNG
- Add the BMP files. Drop them on the upload box or click it to pick them from a folder.
- Conversion is automatic. There are no settings, because PNG has no quality level to choose.
- Download. Save each PNG by itself, or press Download All for a ZIP of the whole batch.
What We Measured
We ran four real BMP files through the converter.
| BMP file | BMP size | PNG size | Change |
|---|---|---|---|
| Photograph, 1280 × 853, 24-bit | 3.12 MB | 2.44 MB | 22% smaller |
| Small logo, 72 × 48, 24-bit | 10 KB | 2 KB | 78% smaller |
| Test pattern, 127 × 64, 24-bit | 24 KB | 2 KB | 90% smaller |
| Test pattern with transparency, 127 × 64, 32-bit | 32 KB | 3 KB | 92% smaller |
Graphics with flat colour shrink the most. A photograph shrinks less, because PNG is not allowed to throw detail away. If a photo has to be small, the BMP to JPG Converter will do far better.
BMP, PNG and Transparency
Most BMP files are 24-bit: red, green and blue for each pixel and nothing else. They have no transparency to keep, and the PNG will have the same solid background. A 32-bit BMP can carry a fourth value for transparency. We tested one in Chrome and the PNG kept its clear and half-clear pixels. Not every program that writes 32-bit BMP files fills that fourth value in, so check the result. Cutting a background out of a picture that never had transparency is a separate job for an image editor.
Where BMP Files Still Come From
Older Windows programs, some scanners, and the software of laboratory and industrial equipment still save BMP, because the format is simple to write. Microsoft Paint offers it in its Save As list too. Converting to PNG is safe in every one of these cases, since nothing in the picture is altered.
Frequently Asked Questions
Does converting BMP to PNG lose quality?
No. A BMP stores each pixel as it is, and PNG compresses without discarding anything. The PNG holds the same pixels in a smaller file.
Will the PNG have a transparent background?
Only if the BMP had one. A 32-bit BMP with an alpha channel keeps its transparency, which we checked in Chrome. An ordinary 24-bit BMP has a solid background, and it stays solid.
How do I make the background transparent?
Converting the format does not remove a background. It has to be cut out in an image editor or a background removal tool after converting. This site does not have one.
How much smaller is the PNG?
It depends on the picture. In our tests a 3.12 MB photograph became 2.44 MB, and small graphics with flat colour became 78% to 92% smaller.
Why are BMP files so large?
A BMP is usually stored without compression: three bytes for every pixel, or four with transparency. A 1280 × 853 picture is over 3 MB whatever it shows.
Are my files uploaded?
No. The conversion runs in your browser and the files stay on your device.