AnyFormat

00 BMP → PNG

BMP to PNG

Lossless, and typically 80–95% smaller.

Drop files or a folder here

or choose from your device · paste with ⌘V / Ctrl+V

.bmp .dib

03Options 4
  • No upload The conversion runs in this tab. Your file never travels — not to us, and not to the advertising.
  • No sign-up, no email, no daily cap There is no account system to sign up to.
  • No size limit we invented Only your device's memory — about ~2 GB on a desktop browser, ~400 MB on a phone.
  • Turn your Wi-Fi off and convert anyway The conversion needs nothing but this page. Ads will not load without a connection; your file will still convert. That is the whole claim, and it takes five seconds to check.

Converts BMP to PNG. Both are lossless, so the pixels are identical — the file just stops being enormous.

Why BMP files are so large

BMP stores pixels essentially uncompressed: roughly four bytes for every pixel regardless of what the image contains. A 1920 × 1080 screenshot is about 8 MB as a BMP and perhaps 300 KB as a PNG — of exactly the same pixels.

PNG applies lossless compression, so nothing is approximated. The image is bit-for-bit identical and the file is a fraction of the size. There is essentially no reason to keep a BMP unless a specific tool demands one.

Where BMPs still come from

Windows utilities, scientific instruments, industrial cameras, embedded systems, and older scanning software — anywhere the simplicity of an uncompressed format mattered more than its size. Screenshots pasted into Paint and saved also default to BMP on older Windows.

Upside-down rows, and the alpha channel that usually is not one

BMP stores its rows from the bottom up unless the height is written as a negative number, which is why a badly written reader shows the image flipped. Both conventions are read. The more common trap is the fourth byte in a 32-bit BMP: it is reserved rather than defined as alpha, and most software writes zeros into it. Read as transparency that makes the whole image invisible, so it is treated as opaque unless the file carries a header that explicitly declares an alpha mask.

Other names for this

Also searched as “bitmap to png”, “convert bmp to png”.

Questions

Is any quality lost?
None. Both formats are lossless; PNG simply compresses the same pixels.
How much smaller will it be?
Typically 80–95% for screenshots and graphics, less for photographic content, but always substantially smaller.
Can I convert a whole folder of images?
Yes. Drop as many files as you like, or a whole folder. Each keeps its original name with the new extension — IMG_4032.heic becomes IMG_4032.jpg, never converted_1.jpg — and you can download them individually or as a ZIP.
Are my photos uploaded?
No. The decoding and re-encoding happen in this tab using the browser’s own image support. Photos are personal in a way most files are not, and none of them is transmitted. Turn your Wi-Fi off and the converter keeps working.
How large an image can I convert?
The practical ceiling is the browser’s canvas limit, about 268 million pixels in total area — roughly 16,000 × 16,000. Above that you get a clear error rather than a silent failure, and resizing first is the fix. File size itself is limited only by your device’s memory.