AVIF and WebP are modern image formats aimed at efficient delivery. They can both handle common web-image needs, but they use different compression technology and have different performance characteristics.
Compression efficiency
AVIF can achieve very compact results for some photographs and gradients, especially when aggressive compression is acceptable. WebP also performs well and can be faster or simpler in many established toolchains. There is no universal file-size winner for every image.
Quality behavior
At low bitrates, formats can fail differently. One image may preserve edges better in one encoder while another preserves texture or gradients better in the other. For important assets, compare actual output rather than relying on a generic percentage claim.
Transparency and modern features
Both formats can support transparency. AVIF also benefits from capabilities inherited from modern video coding technology, while WebP has a longer history in common web workflows.
Operational trade-offs
AVIF encoding can be more computationally demanding. If you generate many images on demand, encoding time and hosting resources matter. WebP may be a simpler operational choice even when AVIF can produce a smaller file in a particular test.
Recommendation
Keep a high-quality source image, generate modern delivery formats and measure your own output. Choose based on visual quality, actual byte size, generation cost and the compatibility requirements of your audience.