Why PNG is a better BMP
BMP and PNG both store images without loss, but BMP usually doesn’t compress at all, while PNG packs the same pixels efficiently. Converting gives you an identical image in a much smaller file, in a format that every browser, website and app supports. Many sites accept PNG but not BMP.
Typical BMP sources:
- screenshots and images saved by older Windows programs
- scanners and document cameras
- lab, industrial and medical equipment exports
- old game and software assets
How to use it
Choose your BMP files or drop them on the box above. Each one is converted on your device and gets its own download button; download several together as a ZIP.
What stays the same
- Every pixel and colour, exactly
- Dimensions
- Transparency, if the BMP has an alpha channel
Only the way the data is stored changes.
Making it even smaller
If the PNG is still larger than you need, the PNG compressor can reduce screenshots and graphics by a further 60–80% by limiting colours. For photos, BMP to JPG produces far smaller files.
Privacy
Files are converted by your browser and never leave your device.
BMPs from instruments and scanners
Microscope cameras, industrial inspection systems, medical devices and older scanners often save BMP because it’s simple to write. For measurements or analysis, a lossless format matters: PNG keeps every pixel value exactly, so images stay valid for comparison while taking a fraction of the space. JPG would alter pixel values slightly, which can matter for scientific work.
Checking the result
Click the small preview next to a converted file to compare it with the original side by side. Because the conversion is lossless, the two should look identical; only the file size changes.
Converting many files
Select or drop a whole folder of BMPs and download the PNGs together as a ZIP file.
Questions
Is BMP to PNG lossless?
Yes. PNG stores every pixel exactly, so the PNG is a perfect copy of the BMP, just compressed.
How much smaller is the PNG?
Screenshots and graphics often shrink by 80–95%. Photos shrink less, typically by 30–60%, because their detail is harder to compress without loss.
Should I use PNG or JPG?
Choose PNG for screenshots, diagrams, text and anything you'll edit. Choose JPG for photos when the smallest file matters more than a perfect copy.
Does it keep transparency?
Yes, in the rare BMP files that have an alpha channel. Ordinary BMPs have no transparency, so the PNG has none either.
Last reviewed 1 November 2026