AV1 Image File Format (AVIF)
AVIF is the next-generation web image format — `<picture>` fallbacks, CDN support, and browser adoption make it worth knowing for asset pipelines and performance work.
What It Defines
Still-image format using AV1 compression inside a HEIF/ISO BMFF container. MIME type: `image/avif`. Supports HDR, wide color gamut, alpha, and metadata. Smaller than JPEG/WebP at similar quality.
Canonical (Normative)
Convenient (Practical)
Industry alliance that publishes royalty-free media codecs and container bindings used on the modern web, notably AV1 video and the AVIF still-image format (AV1 Image File Format, based on HEIF).
Related Specs
WebP delivers smaller files than JPEG/PNG for equivalent quality — widely used for web delivery via `<picture>`, CDN transforms, and Next.js image optimization.
JPEG dominates photo storage and delivery. EXIF metadata (GPS, camera, orientation) lives in APP1 markers — relevant for privacy, image processing, and upload pipelines.
MP4 is the dominant video container on the web and in MSE players. Box hierarchy, codec vs container distinction, and fragmenting (fMP4 for HLS/DASH) are essential for media engineering.