File extension

.heif

High Efficiency Image File Format (HEIF)

.heif files are High Efficiency Image File Format (HEIF) images: an MPEG container for still images and image sequences, standardized as ISO/IEC 23008-12 and often seen with the extensions .heif, .heic, and .avif.

Known meanings

Formats and reference material for .heif

High Efficiency Image File Format (HEIF)

ISO base media file format container for still images, image sequences, and related metadata

  • 2d-graphics
  • MPEG / ISO/IEC
Open link

Details

Format notes

HEIF

HEIF is a container format for storing individual images and image sequences together with their metadata. It is defined in ISO/IEC 23008-12 (MPEG-H Part 12) by the Moving Picture Experts Group. HEIF itself is not a compression method: it describes how coded images are stored, and the codec is chosen by the file’s brand and item types. HEVC is the best known choice (see .heic), and other codecs such as AV1 (.avif) can be carried as well.

Structure

HEIF builds on the ISO base media file format (ISO/IEC 14496-12), the same box structure used by MP4. A file starts with an ftyp box whose major brand tells readers what to expect, for example heic, heix, mif1, or msf1. Images are stored as items described in a meta box. The format supports multiple images per file, thumbnails, auxiliary images such as alpha or depth maps, derived images (for example a grid of tiles forming one large picture), image sequences, and Exif and XMP metadata.

Adoption

Apple adopted HEIF with HEVC coding as the default photo format starting with iOS 11 and macOS High Sierra, and many Android devices and cameras also write it. Support in browsers and operating systems varies, partly because HEVC is covered by patent licensing. The media type is image/heif, with image/heic for the HEVC variant.

Preservation And Security Notes

Because HEIF is a container, preservation records should note which codec, brand, and optional features (derived images, sequences, auxiliary images) are used, as readers may support only a subset. Parsers should validate box sizes, item references, and image dimensions, since the nested box structure has been a source of memory-safety bugs in decoders. Nokia published an open source implementation of the format.

Further Reading

  • Nokia HEIF information and reference implementation: https://nokiatech.github.io/heif/
  • Nokia HEIF source code: https://github.com/nokiatech/heif
  • Library of Congress format description: https://www.loc.gov/preservation/digital/formats/fdd/fdd000525.shtml