APNG (Animated Portable Network Graphics)
APNG is an extension of PNG that adds animation support while maintaining backward compatibility. It supports full 24-bit color with 8-bit alpha transparency in every frame, producing smoother animations than GIF. Non-APNG-aware decoders display the first frame as a static PNG.
MIME Type
image/apng
Type
Binary
Compression
Lossless
Advantages
- + Full 24-bit color with alpha transparency per frame
- + Backward compatible with static PNG viewers
- + Better compression than GIF for same quality
Disadvantages
- − Larger files than WebP or AVIF animations
- − Not an official PNG standard
- − Limited editing tool support
When to Use .APNG
Use APNG instead of GIF when you need animations with full color and alpha transparency, such as animated stickers and UI elements.
Technical Details
APNG adds fcTL and fdAT chunks to the PNG specification for frame control and data. Each frame can have independent timing, disposal, and blending operations.
History
APNG was created by Mozilla developers Stuart Parmenter and Vladimir Vukicevic in 2004. It was rejected by the PNG group but gained browser adoption and became widely supported by 2017.