image/heic

What iPhones shoot by default: HEVC-compressed images inside the ISO/IEC 23008-12 HEIF container. It halves JPEG's file size, but HEVC's patent licensing has kept decoders out of most browsers, so the classic trap is an upload pipeline receiving .heic files it cannot thumbnail — convert to JPEG or WebP at the edge rather than serving HEIC to the web. Like all ISO-BMFF formats it identifies itself in the ftyp box at offset 4, brand heic (heix and friends exist for other profiles).

Defined by HEIF technical overview (ISO/IEC 23008-12) · IANA registration. Registry facts from the IANA media-types registry via mime-db.