Convert BMP to PNG Online — Free
Convert BMP to PNG online — lossless output with transparency support and far smaller files than BMP. Free, private, runs entirely in your browser.
Direct converter coming soon
Image Compressor accepts BMP and outputs the same format. A direct BMP → PNG tool is on the roadmap.
Open Image Compressor →How to convert BMP to PNG
- 1
Add your BMP file
Drop or select a .bmp file. Files up to 50MB process locally in your browser — nothing uploaded.
- 2
Run the conversion
We decode your BMP via the browser's image decoder and re-export as PNG with DEFLATE compression. Every pixel is preserved exactly (lossless in both directions), and the file shrinks significantly because PNG compresses while BMP doesn't.
- 3
Download your PNG
One click saves the result as a .png file. Your original file stays on your device.
Why convert BMP to PNG?
PNG is lossless like BMP but uses smart DEFLATE compression, typically producing files 2-5× smaller. If you need lossless quality without BMP's uncompressed bloat — for editing, archiving, or sharing graphics — PNG is the modern answer. BMP is a legacy Windows format; PNG is the universal lossless standard.
Common BMP to PNG use cases
- Archiving BMP graphics from legacy Windows applications at 2-5× less disk space while staying lossless
- Preparing BMP icons or sprites for use on the web (where BMP is unsupported outside Chrome)
- Migrating bitmap archives from old CAD, GIS, or industrial imaging tools to a universally readable format
- Converting screenshots from older Windows utilities to PNG for inclusion in documentation or blog posts
What file size to expect
A 1920×1080 uncompressed 24-bit BMP is exactly 6.22 MB. The same image as PNG is typically 500 KB-2 MB for photos and 100-400 KB for screenshots or flat graphics — 3-15× smaller. Line art and UI graphics compress best because PNG's DEFLATE excels at repeated pixel patterns.
Technical notes: BMP → PNG
BMP stores raw pixel data in BGR channel order with optional alpha (BITMAPV4/V5 headers); PNG stores pixel data compressed with DEFLATE plus optional filter prediction for better compression. Both are truly lossless — every pixel preserved. If the BMP has an alpha channel, PNG preserves it. Embedded ICC profiles (rare in BMPs, common in BITMAPV5) are dropped by Canvas-based conversion; colors are interpreted as sRGB during rendering.
Compatibility and browser support
PNG is supported in every browser, OS, photo viewer, and design tool since 1996 — the gold standard for lossless images. BMP input works in every modern browser (Chrome, Firefox, Safari, Edge) for standard 24/32-bit variants. Rare RLE-compressed BMPs may fail to decode.
BMP vs PNG
| BMP | PNG | |
|---|---|---|
| File size | Very large (uncompressed) | Larger (lossless) |
| Quality | Lossless | Lossless |
| Transparency | Limited (some variants) | Yes |
| Browser / app support | Universal but rarely used | Universal |
| Best for | Legacy Windows applications | Screenshots, logos, graphics with transparency |
Related conversions
Frequently Asked Questions
Will I lose any quality?
No — both BMP and PNG are lossless. Every pixel is preserved exactly during this conversion.
PNG vs BMP — how much smaller?
Typically 2-5× smaller for photos, 5-15× smaller for screenshots, line art, and graphics with flat color regions.
Do I need any plugins?
No — runs in any modern browser. BMP decoding is built into every major browser's image pipeline.
Does transparency survive?
Yes — if your BMP uses a 32-bit header with alpha (BITMAPV4 or V5), the alpha channel is preserved in the PNG.
Why is my specific BMP bigger as PNG?
Rare — usually happens with highly noisy images where DEFLATE can't find patterns. If it does, try PNG's alternate filter modes via a desktop tool like pngcrush.
Will colors shift?
No — pixel values are preserved exactly. BMP's BGR order converts to RGB during decoding without any value change.