BMP to PNG Converter - Convert BMP to PNG Online Free

How to convert BMP to PNG

Add your BMP files. Drop up to 50 BMP or DIB images into the box, or browse for them. They never leave your device.
Pick a PNG type. Smallest (the default) is lossless and packs the file tightly, Standard is the quickest, 8-bit makes tiny files. The PNG size shown is measured from the real file.
Adjust if you like. Keep or fill transparency, resize, keep the DPI or rename the files - every option is one click away and starts closed.
Convert and download. Press Convert to PNG. One or two files download directly, more than two come as a ZIP.

Want the PNG as a Windows or website icon next? Drop it into the PNG to ICO converter.

Why convert BMP to PNG?

BMP stores every pixel raw, with no compression at all.

A 1920 x 1080 screenshot weighs about 6 MB as a BMP.

As a PNG the same image is often 5-10 times smaller and looks exactly the same, because PNG is lossless too. Email, websites and chat apps take it without complaint.

BMP vs PNG

	BMP	PNG
Compression	None (or simple RLE)	Lossless (Deflate)
Typical size	Huge - about 3 bytes per pixel	Often 5-10x smaller
Transparency	Only 32-bit, patchy support	Full alpha, everywhere
Colour depth	1 to 32-bit	1 to 48-bit, palette, grey
Opens in	Windows apps, Paint, editors	Every browser and app
Best for	Legacy software, raw pixel data	Web, sharing, screenshots, logos

Going the other way for an old program? Use PNG to BMP. Need test files? Try the BMP sample files.

Every kind of BMP, read properly

All bit depths - 1-bit black and white, 4 and 8-bit palettes, 16-bit (5-5-5 and 5-6-5), 24-bit and 32-bit.
Compressed BMPs - RLE4 and RLE8 files are decoded by our own parser, not left to chance.
Odd headers - V4 and V5 headers, bitfields, top-down rows and old OS/2 bitmaps all work.
Transparency - the alpha channel of a 32-bit BMP becomes PNG transparency. Pick Fill background for a solid colour instead.

Curious what is inside a file? The BMP Analyzer shows every header field.

Tips for smaller PNGs

Screenshots and diagrams? Smallest often saves them as a palette PNG with no loss at all.
Photos? PNG keeps every pixel, so photos stay big. BMP to JPG or BMP to WebP make much smaller files.
Need it tiny? The 8-bit palette cuts most files by another 60-80%.
Still too big? Run the result through Compress PNG.

Frequently Asked Questions

Drop your BMP files into the box, keep the default Smallest PNG type or pick a preset, and press Convert to PNG.

One file downloads as a PNG, more than two come as a ZIP.

No. Your browser reads the BMP and writes the PNG on your device. Nothing is sent anywhere, so private screenshots and scans stay private.

No. PNG is lossless, so every pixel is saved exactly. Only the 8-bit palette type reduces colours, and the page warns you when it is on.

BMP stores raw pixels, while PNG packs them with lossless compression. Screenshots and graphics often shrink to a tenth of the size.

The size shown is measured from the real PNG before you download.

Yes. The alpha channel of a 32-bit BMP becomes PNG transparency. Most BMPs are 24-bit and have no transparency, so they stay fully opaque.

1, 4, 8, 16, 24 and 32-bit BMP and DIB files, uncompressed or RLE4/RLE8 compressed, with bitfields, V4/V5 headers, top-down rows and OS/2 headers. The DPI is kept too.

Up to 50 BMP files per batch, up to 300 MB each. Recent conversions stay in this browser, so you can download them again later.

Yes - use PNG to BMP. Because PNG is lossless, the round trip gives you the same pixels back.