Short answer: To convert BMP to PNG, drop the file above, choose PNG and click Convert. The pixels stay identical, but the file is usually much smaller because PNG compresses without losing detail.
If you want to shrink a BMP without losing a single pixel of detail, PNG is the answer. Both formats store the picture exactly, but PNG compresses it cleverly, so the file is usually much smaller. This page converts BMP to PNG inside your browser, so your pictures never leave your device.
Lossless means identical pixels
PNG compression works like zipping a file: nothing is thrown away, and the decoded picture is exactly the one that went in. That makes PNG the right target for screenshots, diagrams, scans of line art and anything where edges and text must stay sharp. You get smaller files with no change in appearance, which JPG cannot promise.
How much space do you save?
Flat graphics and screenshots shrink enormously, often to a few percent of the BMP size, because they contain large areas of identical color. Photographs shrink less, since their pixels vary. The results list shows the before and after sizes for every file so you can see where the savings are largest.
Limits and tips
Everything is free, and you can convert many files at a time. BMP has no transparency in the files this page creates, so the PNG will be fully opaque. If you only need a small copy for email and perfect detail is unimportant, JPG will be smaller still. Use the resize options if you want fewer pixels as well.
A lossless clean-up
This conversion is a safe way to reduce an archive without changing a single pixel. After converting, you can compare a few files by opening both versions and zooming in; they should look identical. Keep the BMPs until you are sure everything arrived, then free the space. Flat graphics from old software, such as diagrams and interface captures, benefit most, since PNG handles large flat areas very well. For photographs, expect smaller savings, and consider JPG if you can accept a tiny loss. Naming the files with a rename pattern such as {name}-lossless keeps the two versions easy to tell apart while you check them.
Questions people ask
Does BMP to PNG lose any quality?
No. PNG is lossless, so the pixels are identical to the BMP.
Why is the PNG smaller?
PNG compresses the picture without discarding detail, while BMP stores every pixel uncompressed.
Is my file uploaded?
No. The conversion runs in your browser and the picture stays on your device.
Is a PNG made from a BMP really identical?
Yes. Both store pixels without loss, so the picture is the same. PNG simply packs it far more efficiently.
Can I use the PNG in the same old program that made the BMP?
Many old programs read PNG, but not all. If yours does not, keep the original BMP for that program and use the PNG everywhere else.
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Last reviewed: October 17, 2026