AVIF (AV1 Image File Format) is a modern image format derived from the AV1 video codec that delivers significantly smaller file sizes than JPEG and WebP at comparable visual quality. Smaller images load faster and directly benefit [Largest Contentful Paint (LCP)](/glossary/lcp) scores. AVIF supports HDR, wide colour gamut, and transparency, making it a versatile replacement for older formats. Browser support is now broad — Chrome, Firefox, and Safari all support it — though serving a WebP or JPEG fallback via the HTML `` element remains good practice for older clients.