AVIF

AVIF (AV1 Image File Format) is a modern image format derived from the AV1 video codec. Standardised in 2019. Compresses 20-30% smaller than WebP at equivalent visual quality.

Like WebP, AVIF supports both lossy and lossless modes, full alpha (transparency), animation, HDR, and wide colour gamuts. Unlike WebP it’s expensive to encode — encoders can take 10× to 100× longer than equivalent WebP encoding for the same input. Decoding is fast (the AV1 video decoder is well-optimised, including hardware acceleration on recent CPUs and GPUs).

Browser support as of 2026: ~93% globally. Chrome since 2020, Firefox since 2021, Safari since 2022. Older Android and Apple devices still miss out.

When AVIF is worth the encoding cost:

• Image-heavy sites where page weight is critical — e-commerce hero images, gallery sites, news media.
• CDN-delivered images where the encoding happens once at upload time.
• Mobile-first audiences on metered connections — the 20-30% bandwidth savings compound.

For most workflows, WebP is the easier default and AVIF is a worthwhile optimisation when you already have a build pipeline producing multiple format variants and shipping them via <picture> fallback.