EPUB to AVIF Converter

AVIF (AV1 Image File Format) is a modern image format derived from the AV1 video codec, developed by the Alliance for Open Media and specified in February 2019. The format leverages the intra-frame coding tools of AV1 — a royalty-free video codec backed by Google, Apple, Microsoft, Amazon, Netflix, and other major technology companies — to compress still images with substantially higher efficiency than JPEG, PNG, or even WebP. AVIF stores images in the HEIF (High Efficiency Image File Format) container, supporting both lossy and lossless compression, HDR (high dynamic range) with wide color gamuts up to 12-bit depth, alpha transparency, and animated sequences. At equivalent visual quality, AVIF files are typically 30-50% smaller than WebP and 50-70% smaller than JPEG, representing the largest compression improvement in mainstream image formats in over a decade. One advantage is exceptional compression efficiency — AVIF delivers visually indistinguishable images at dramatically lower file sizes, directly reducing bandwidth consumption and improving page load times for web content. The royalty-free licensing model provides another key strength: unlike HEIC/HEIF which relies on patent-encumbered HEVC, AVIF's AV1 foundation is free for anyone to implement without licensing fees. Browser support has reached broad adoption, with Chrome, Firefox, Safari, and Edge all rendering AVIF natively. The format is rapidly gaining adoption for web images where quality-to-size ratio is paramount.