What is AVIF?
AVIF (AV1 Image File Format) stores still images compressed with AV1, the royalty-free video codec from the Alliance for Open Media, whose members include Apple, Google, Microsoft, Mozilla and Netflix. It arrived in 2019 and typically beats both JPEG and WebP on file size at the same visual quality, especially on smooth gradients and skies.
AVIF supports transparency, wide colour and HDR. Chrome, Edge, Firefox and Safari all display it.
AVIF or WebP?
If the smallest possible file matters most, for a hero image or a photo-heavy page, use AVIF. If you need to convert thousands of images quickly, or support older devices, WebP is faster to encode and even more widely supported. Many sites serve AVIF with a WebP or JPEG fallback using the HTML <picture> element.
Why resize as well
The biggest saving on the web usually comes from size, not format. A 24-megapixel photo shown 1,200 pixels wide wastes most of its pixels. Squeezels resizes and converts in one pass. The example above was resized to 2,560 pixels and converted at quality 80%.
