About the BMP to PNG
PNG is the modern replacement for BMP: both keep every pixel exactly, but PNG compresses the data, so files are often a half to a tenth of the size and open in every browser, phone and app. This converter turns BMP images into PNG in bulk, keeping the full resolution and any transparency. It is the right choice for screenshots, icons, diagrams, scans of documents and pixel art, where JPG would blur sharp edges. Everything runs in your browser.
Updated October 2026
How to use the BMP to PNG
- 1Click Select images, or drop BMP files on the page.
- 2Wait while each image converts.
- 3Check the new file sizes.
- 4Download each PNG or all of them as a ZIP.
- 5Delete the old BMPs once you've checked the results.
Why PNG is the better bitmap
BMP dates from early Windows and has no compression in most files. PNG arrived in 1996 as a free, compressed and lossless format, and today every operating system and browser supports it. Converting old bitmaps to PNG saves storage and makes them easy to share, without changing a single pixel.
Good uses for PNG
Choose PNG whenever exact pixels matter.
- Screenshots with text
- Logos and icons, especially with transparency
- Diagrams, charts and maps
- Scanned forms you may edit
- Pixel art and game sprites
Checking the result
Open the PNG next to the BMP at 100% zoom: they should look identical. The thumbnail in the list shows the converted picture, and the row shows the size so you can see the saving.
Archiving old files
If you are tidying a folder of old BMP scans, convert the whole folder at once and download the ZIP. Keep the originals until you have checked a few results, then delete them to free space.
How PNG compresses without losing anything
PNG first predicts each pixel from its neighbours and stores only the difference, then squeezes the result with the same Deflate method used in ZIP files. Areas of flat colour, like the background of a screenshot, become almost nothing, while the exact pixel values are always restored when the image is opened.
Typical savings
Results vary with the picture, but these are common for 24-bit bitmaps.
- Screenshots and diagrams: 85–98% smaller
- Scanned text documents: 70–90% smaller
- Cartoon and flat artwork: 80–95% smaller
- Photos: 20–50% smaller
Colour accuracy
PNG stores the same red, green and blue values as the BMP, so colours don't shift. If you later edit the PNG and save it again, nothing is lost, which is why designers keep working files as PNG rather than JPG.
On any device
The converter works the same in Chrome, Safari, Edge and Firefox on phones and computers. For a smaller photo file, use BMP to JPG, and if you need another type, the Image Converter lists more formats. The Image Converter handles other formats too, and JPG to PNG is the choice when your photo is already a JPG.
Features
- Lossless: every pixel kept
- Smaller than BMP
- Transparency preserved
- Batch conversion
- ZIP download
- Runs on your device
Frequently asked questions
Is BMP to PNG lossless?
Yes. PNG stores exactly the same pixels as the BMP, just compressed. Converting back would give an identical image.
How much smaller will my files be?
It depends on the picture. Screenshots and graphics with flat colours often shrink by 80 to 95%; noisy photos shrink less, sometimes only 20 to 40%.
Should I use PNG or JPG?
PNG for screenshots, text, logos and anything you will edit again. JPG for photos where the smallest file matters.
Does it keep transparency?
Yes, if the BMP has an alpha channel (32-bit BMPs can). Most BMPs are fully opaque.
Can I convert on a phone?
Yes. Pick BMP files from your phone's files app; the PNGs download to your phone.
Are files uploaded?
No, conversion happens entirely in your browser.
Does it change the number of pixels?
No. Width and height stay the same; only the way the pixels are stored changes.
Why is my PNG not much smaller?
Photos with lots of fine detail and noise compress less losslessly. For those, BMP to JPG gives a far smaller file.