apng.dev
APNG Fundamentals

What is APNG?

APNG (Animated PNG) extends PNG with timeline metadata and frame payload chunks. You get smooth animation without giving up PNG quality and transparency.

Core idea

APNG stores a normal PNG image plus animation chunks such as acTL, fcTL, and fdAT. This design keeps broad decoder compatibility while enabling frame-by-frame playback.

APNG is an extension of PNG that supports multiple animation frames.

It keeps true 24-bit color plus 8-bit alpha transparency.

Modern browsers render APNG natively with no JavaScript runtime.

If animation is unsupported, many decoders still display the first PNG frame.

When APNG is a strong choice

  • UI animations needing crisp alpha edges and rich colors.
  • Animated overlays that would band heavily in GIF.
  • Assets where visual fidelity matters more than absolute smallest bytes.