What is AVIF Image Format?

This article provides a comprehensive overview of the AV1 Image File Format (AVIF), exploring what it is, how it works, and why it is rapidly becoming the preferred image format for the web. You will learn about its key benefits, how it compares to older formats like JPEG and WebP, its current browser support, and how to start implementing it using official libraries.

Understanding AVIF

AVIF stands for AV1 Image File Format. It is a modern, open-source, and royalty-free image file format specification designed to store still and animated images compressed with the AV1 video codec. Developed by the Alliance for Open Media (AOMedia)—a consortium that includes tech giants like Google, Apple, Microsoft, Mozilla, and Netflix—AVIF was created to significantly reduce image file sizes without sacrificing visual quality.

Key Benefits of AVIF

AVIF offers several technical advantages over legacy formats:

Superior Compression: AVIF can compress images up to 50% smaller than JPEG and up to 20% smaller than WebP while maintaining the same perceived visual quality.
High Dynamic Range (HDR): It supports 10-bit and 12-bit color depth, enabling HDR images with brighter whites, deeper blacks, and a wider color gamut.
Transparency and Animation: Like PNG, AVIF supports transparency (alpha channel). Like GIF, it supports animated image sequences, but at a fraction of the file size.
Lossless and Lossy Compression: Users can choose between lossy compression (smaller file size, minor quality loss) and lossless compression (larger file size, perfect quality retention).

AVIF vs. JPEG and WebP

While JPEG has been the web standard for decades, it suffers from severe quality degradation at high compression rates. WebP improved upon JPEG by offering 30% smaller files, but AVIF surpasses WebP by leveraging the advanced compression algorithms of the AV1 video codec.

In real-world web performance, serving AVIF images leads to faster page load times, reduced bandwidth consumption, and a better user experience, particularly on mobile networks.

Browser and Software Support

Today, AVIF enjoys widespread support across all major web browsers, including Google Chrome, Mozilla Firefox, Apple Safari, and Microsoft Edge. Major operating systems and image editing software also natively support viewing and exporting AVIF files.

How to Implement AVIF

To start using AVIF on your website, you can use the HTML <picture> element to serve AVIF to compatible browsers while falling back to WebP or JPEG for older browsers:

<picture>
  <source srcset="image.avif" type="image/avif">
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Example Image">
</picture>

For developers looking to encode, decode, and manipulate AVIF files programmatically, the official library is libavif. You can find comprehensive guides, API references, and usage instructions on the online documentation website for libavif at libavif.web.app.