Free, no account, no watermark. Your BMP files are turned into PNG inside this browser tab — they are never uploaded to a server.
Nothing leaves your device
No account, no email
Free, and no watermark
Drop your files here
Tap to pick your photos
or
Choose files
Up to 30 files at a time · 60 MB per file
Advertisement
Ad slot — inactive until AdSense approval
Why convert BMP to PNG?
The conversion to reach for when the BMP needs to get much smaller without giving up a single pixel. PNG is lossless, so the result is mathematically identical to the original, usually at a quarter of the size or better. Pick this over JPG whenever the image contains text, diagrams or screenshots.
Choose PNG when transparency has to survive, or when the image will be edited again. Text, logos, screenshots and line art all come through a PNG round-trip completely untouched.
How to convert BMP to PNG
Drop your BMP files into the box above, or click to pick them from your device.
Hit convert. The work happens inside your browser, so it takes a second or two per image.
Download each PNG file, or grab them all in one ZIP.
About the formats
BMP — Windows Bitmap
BMP stores pixels essentially raw, with little or no compression at all. That makes it trivially simple for software to read and absurdly large to keep around: a photo that would be 2 MB as JPG can comfortably run past 20 MB as BMP. It survives mostly inside Windows software, scanner drivers and older industrial tools.
Strengths
Completely lossless, with no compression to undo
A dead-simple format that even very old software can read
No patents and no licensing questions attached
Limitations
Wildly larger than any modern format, often by ten times or more
No meaningful compression whatsoever
Effectively unsupported outside the Windows world
PNG — Portable Network Graphics
PNG is lossless: what goes in comes back out pixel for pixel, no matter how many times you re-save it. Add a full alpha channel and you have the natural home for logos, screenshots, diagrams and anything with hard edges or text. The cost is weight — a photograph stored as PNG can be five times heavier than the same photo as JPG.
Strengths
Lossless — no compression artefacts, at any number of re-saves
Full alpha transparency, including soft anti-aliased edges
Universal support, and the default for screenshots and interface assets
Limitations
Far heavier than JPG or WebP for photographic content
No quality dial — you take the file size you are given
Slower to decode at very large dimensions
Advertisement
Ad slot — inactive until AdSense approval
Frequently asked questions
Are my photos uploaded anywhere?
No. The conversion runs entirely in your browser using WebAssembly and the Canvas API. Your images are never sent over the network, never touch a server, and are dropped from memory as soon as you close the tab.
Will I lose quality?
PNG is lossless, so the output is a pixel-for-pixel copy of what was decoded from the original. The file will usually be bigger than the source, which is the price of keeping every pixel intact.
Is there a limit or a cost?
It is free and there is no account. The only limits are practical: 30 files at a time and 60 MB per file, so that the tab does not run out of memory on a phone.
Can I convert several files at once?
Yes — drop in up to 30 files and they are processed one after another, then downloaded individually or as a single ZIP.
Does it work offline?
Once the page has loaded, yes. The converter itself needs no network connection, so you can drop the connection and keep converting.
Does it work on a phone?
Yes, on iOS and Android. Large batches are slower on a phone because the decoding happens on the device, so stick to smaller groups if things feel sluggish.