.apng File — Animated Portable Network Graphics

APNG (Animated PNG) is an extension of the PNG format that adds support for animated images, serving as a modern alternative to GIF animations. APNG was proposed by Mozilla developers in 2004 and works by storing multiple PNG frames with individual timing and disposal information within a standard PNG container. APNG offers significant advantages over GIF — it supports 24-bit color with 8-bit alpha transparency (vs GIF's 256-color palette and binary transparency), resulting in smoother gradients and cleaner edges in animations. APNG files maintain backward compatibility with regular PNG — software that doesn't support APNG will display the first frame as a static PNG image. The format is now supported by all major web browsers including Chrome, Firefox, Safari, and Edge. Despite its technical superiority over GIF, APNG hasn't achieved mainstream adoption partly because the official PNG group rejected the proposal and partly because WebP and AVIF also support animation. APNG remains particularly popular for high-quality animated stickers, emoji, and UI elements where smooth transparency is essential.