Convert BMP to PNG
PNG gives you the same lossless fidelity as BMP but with proper compression, so files are typically 2–5× smaller. It's the right modern replacement for BMP whenever you need pixel-perfect images.
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To convert BMP to PNG, drop your bitmap above and download the PNG. PNG is lossless like BMP but uses DEFLATE compression, so the file is typically 50–80% smaller with pixel-identical output. Ideal for scanned documents, retro pixel art, and any place you want to keep a BMP's exact fidelity without wasting disk space.
Drop a BMP here, or click to upload
Output: PNG
What BMP to PNG conversion actually does
BMP stores raw RGB pixel data with no compression, while PNG stores the same pixels with lossless DEFLATE. That is why the conversion is safe for pixel-critical work: every pixel value is preserved, only the on-disk encoding is smarter. PNG also supports optional gamma and color-profile tags, so long-term archives are more colour-manageable than BMP. Software developers converting retro-game sprite sheets, GIS tools converting map raster tiles, and scanner users converting document archives all benefit from the lossless size reduction.
Common mistakes and limitations when going from BMP to PNG
PNG has no built-in support for BMP's rare metadata quirks (some scanner-specific chunks are dropped). Extremely large BMPs — over 100 MP — take noticeable time to encode because DEFLATE is single-threaded in the browser. And while PNG supports 16-bit-per-channel data, canvas re-encoding only exposes 8-bit; if you have a scientific BMP with genuinely deeper color, use a dedicated 16-bit-aware tool.
BMP to PNG conversion FAQ
- Is PNG truly lossless?
- Yes. Every pixel value in the BMP is copied into the PNG exactly — only the on-disk encoding changes.
- Does PNG preserve BMP transparency?
- Standard BMPs are opaque, so the PNG will be opaque too. Rare BMPv5 alpha data is preserved.
- How much smaller will the PNG be?
- Usually 50–80% smaller than the BMP, depending on image content. Flat graphics compress the most; noisy photos the least.
- Can PNG replace BMP everywhere?
- For nearly all modern uses, yes. The only holdout is legacy Windows or industrial software that specifically requires BMP input.
- Does the PNG open in old software?
- PNG has been universally supported since 1996 — every browser, editor, mobile OS and word processor reads it.
- What about 16-bit-per-channel BMPs?
- The browser canvas API is limited to 8 bits per channel, so genuine 16-bit scientific data will be down-sampled. Use a dedicated tool for those.
- Will scanned documents stay sharp?
- Yes — DEFLATE is lossless, so text edges and fine strokes are preserved exactly.
- Can I convert very large BMPs?
- Files up to 100 MB are supported. Very large images take a few seconds to encode in-browser.
BMP vs PNG at a glance
| Property | BMP source | PNG output |
|---|---|---|
| Compression | None | Lossless DEFLATE |
| Typical size (12 MP image) | 35–75 MB | 8–20 MB |
| Transparency | Rare (BMPv5 only) | Yes (8-bit) |
| Compatibility | Windows-first | Universal |
| Best used for | Legacy Windows workflows | Modern lossless archive |
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References: Microsoft BMP File Format specification, ISO/IEC 15948 (PNG), libpng documentation on DEFLATE efficiency for bitmap sources.