High Efficiency Image File Format (HEIF/HEIC)
iPhone photos default to HEIC — upload pipelines, image conversion services, and CDN transcoding need to handle this container. AVIF shares the same HEIF structure with AV1 instead of HEVC.
What It Defines
Image container based on ISO BMFF (`ftyp` brands `heic`, `heix`, `mif1`) carrying HEVC (H.265) or AV1 compressed stills, bursts, and auxiliary items (depth, alpha). `.heic` is the common Apple/iOS extension. MIME types: `image/heic`, `image/heif`.
Canonical (Normative)
Convenient (Practical)
Joint ISO/IEC technical committee (JTC 1) publishes many of the binary file formats the web depends on: JPEG, PDF, MP4/ISOBMFF, ZIP (ISO/IEC 21320), and office document containers. Specs are often available via national body mirrors; some are freely readable online.
Related Specs
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.
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.
JPEG dominates photo storage and delivery. EXIF metadata (GPS, camera, orientation) lives in APP1 markers — relevant for privacy, image processing, and upload pipelines.