Convert BMP to APNG Online Free
Convert BMP bitmap images to APNG format for use in modern web workflows and applications that support Animated PNG containers with full transparency.
By ChangeThisFile Team · Last updated: March 2026
ChangeThisFile converts BMP to APNG instantly in your browser using the Canvas API. No file upload needed — your Windows bitmap is converted to a static APNG file locally on your device. Drop your file and download the result in seconds. Free and completely private.
Convert BMP to APNG
Drop your BMP file here to convert it instantly
Drag & drop your .bmp file here, or click to browse
Convert to APNG instantly
BMP vs APNG: Format Comparison
Key differences between the two formats
| Feature | BMP | APNG |
|---|---|---|
| Compression | Uncompressed or minimal RLE | Lossless PNG compression |
| File size | Very large | Much smaller |
| Animation | No | Yes (multi-frame capable) |
| Transparency | Limited (32-bit only) | Full alpha channel |
| Web use | Not suitable | Modern browsers |
| Platform | Windows native | Cross-platform web |
| Best for | Legacy Windows apps | Web graphics, UI elements |
When to Convert
Common scenarios where this conversion is useful
Migrating legacy Windows graphics to web
Old Windows applications produce BMP files. Converting to APNG (or PNG) makes these assets usable in modern web projects with proper compression and cross-platform support.
Adding transparency to BMP images
BMP has poor transparency support. Converting to APNG gives you full alpha channel transparency, which is essential for web overlays, icons, and design work.
Reducing file size for storage
BMP files are uncompressed and extremely large. Converting to APNG typically reduces file size by 70-90% due to PNG's efficient lossless compression.
Preparing images for PNG-based pipelines
APNG is a PNG superset. Converting BMP to APNG makes images compatible with any tool that accepts PNG, while also supporting future animation expansion if needed.
How to Convert BMP to APNG
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1
Select your BMP file
Drag and drop your BMP file onto the converter, or click browse to choose from your files.
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2
Instant conversion
The browser decodes your BMP and encodes it as a static APNG using the Canvas API. No upload needed and no data leaves your device.
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3
Download the APNG
Save your converted APNG file. Ready to use in modern web browsers and any application that supports PNG-compatible images.
Frequently Asked Questions
No. A BMP is a static image, so the output is a single-frame APNG — effectively a standard PNG stored in an APNG container. It displays as a static image in all browsers.
No. BMP is uncompressed and APNG uses lossless PNG compression. The conversion is lossless — every pixel is preserved exactly.
Significantly smaller. BMP stores pixels without compression, while PNG uses lossless LZW compression. A typical conversion reduces file size by 50-90% depending on image content.
No, not automatically. The APNG will contain whatever pixel data was in the BMP. If the BMP has a 32-bit alpha channel, it is preserved. Most BMPs are 24-bit with no transparency.
For a single static image, APNG and PNG are identical — APNG is a backward-compatible extension of PNG. Every APNG is also a valid PNG file.
Yes. All modern browsers support APNG. The file will display as a static image since the BMP source has no animation frames.
No. ChangeThisFile processes everything in your browser using the Canvas API. Your BMP file is never uploaded or transmitted anywhere.
The Canvas API can decode standard 24-bit and 32-bit BMP files. Very old 1-bit, 4-bit, or 8-bit indexed BMPs may or may not decode correctly depending on your browser.
Yes. ChangeThisFile supports APNG to BMP conversion as well. The round-trip is lossless.
For a static image, plain PNG and APNG behave identically. Choose APNG if you plan to add animation frames later, or if your workflow specifically requires APNG format.
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