BMP to PNG: identical pixels in a fraction of the space
This BMP to PNG converter turns bulky Windows bitmaps into PNG files without changing a single pixel. Both formats are lossless, so the picture stays exactly the same — but PNG compresses it, often to a small fraction of the BMP’s size. Convert one file or a batch in your browser and download the PNGs individually or as a ZIP.
PNG is the natural successor to BMP for screenshots, diagrams, icons, pixel art, scanned documents and anything with text. It is supported everywhere — browsers, phones, office suites and design tools — and it keeps the transparency of 32-bit bitmaps.
How to use the BMP to PNG Converter
- Drop BMP or DIB files on the upload area, click it to choose, or paste an image with Ctrl+V.
- Conversion starts immediately. There are no settings to get wrong, because PNG is lossless.
- Check the new sizes, and click a thumbnail to preview the result.
- Download single PNGs, or everything at once with Download all.
BMP to PNG Converter features
Pixel-for-pixel identical
The PNG contains exactly the pixels decoded from the BMP — ideal for screenshots, interface captures and pixel art.
Much smaller files
PNG’s DEFLATE compression removes the redundancy that BMP stores uncompressed.
Transparency kept
32-bit bitmaps with an alpha channel convert to PNGs with the same transparency.
Palette and high-colour BMPs
1-, 4- and 8-bit palette images and 16-bit bitmaps are read as your browser decodes them.
Batch, private, free
No uploads, no watermark, any number of files and one ZIP.
How PNG shrinks a bitmap without losing anything
A BMP stores every pixel as raw numbers. PNG first runs each row through one of five prediction filters — None, Sub, Up, Average or Paeth — which replace pixel values with the small differences from their neighbours. Those differences are then compressed with DEFLATE, the algorithm also used in ZIP files. Decompressing reverses both steps exactly, so the PNG decodes to precisely the original pixels.
How much you save depends on the content. Screenshots, charts and diagrams with flat colour often compress enormously; noisy photos compress less, though they still end up well below the BMP size. For photos where a small loss is acceptable, BMP to JPG makes much smaller files.
Bitmap facts worth knowing
- BMP stores rows bottom-up by default and pads each row to a multiple of four bytes; PNG stores rows top-down with no padding.
- BMP writes each pixel in blue-green-red order; PNG uses red-green-blue.
- A 24-bit BMP of 1920 × 1080 pixels is always 6,220,854 bytes, whatever it shows. A PNG’s size depends on the content.
- PNG was published in 1996 and became the international standard ISO/IEC 15948 in 2004; every browser and operating system reads it.
- BMP files carry no EXIF camera data, so there is nothing to keep or strip.
Where to use the PNG next
Put screenshots straight into documents and emails, upload them to websites, or combine several into one file with PNG to PDF. Need smaller dimensions for the web? The image resizer scales PNGs cleanly, and PNG to WebP can shrink them further for websites.
BMP to PNG Converter FAQ
How do I convert BMP to PNG?
Drop the BMP files on the converter. The PNGs are created immediately with identical pixels; download them individually or as a ZIP.
Is BMP to PNG conversion lossless?
Yes. Both formats are lossless and the PNG holds exactly the pixels decoded from the bitmap, so the image looks identical.
Why is the PNG so much smaller than the BMP?
BMP files are usually uncompressed, while PNG compresses the data losslessly. Images with flat areas of colour shrink the most.
Does it keep transparency from 32-bit BMPs?
Yes, when your browser decodes the bitmap’s alpha channel, as current Chrome and Edge do for V4 and V5 bitmaps. The transparency then carries straight into the PNG.
Should I use PNG or JPG for my bitmaps?
PNG for screenshots, text, diagrams and pixel art; JPG for photographs when you want the smallest files and can accept a tiny loss.
Can I convert BMP to PNG on a phone?
Yes. The converter runs in any modern mobile browser: pick the files and download the PNGs. Nothing is uploaded.
Why do some programs still save BMP files?
BMP is very simple to write — no compression library is needed — so scanners, machine-vision cameras, lab instruments and older Windows programs still produce it. Converting to PNG afterwards gives you exactly the same image at a manageable size.