Get the smallest file a browser can still read.
This file stays on your device
Drop files here
Up to 30.0 MB
Lower makes a smaller file.
AVIF is the smallest of these formats by a wide margin, often half of WebP for the same appearance, and it keeps a transparent background. For a picture that will be served to many people, the saving is real bandwidth and a faster page.
Encoding is slow. A large picture takes seconds in the browser rather than an instant, because the format works harder to get small. Support is good in current browsers and absent in old ones.
Do not use AVIF for a file you are sending to a person rather than serving from a page. Many programs still do not open it. WebP is the safer small format.