All about HEIF files

The High Efficiency Image File Format (HEIF) is a container format for images and image sequences. It was published in 2015 by the Moving Picture Experts Group (MPEG) as part of the MPEG-H standard. Unlike other image formats such as JPEG or PNG, HEIF does not define the compression itself, but rather provides the container for the image data. This is comparable to video container formats such as .MKV or .MP4. Since the codec ultimately used for the image is open, the standard remains flexible for future developments.

Technical Details of the HEIF Container

Technically, HEIF is based on the ISO Base Media File Format (ISO BMFF), which also underlies MP4 and other media containers. This development illustrates how the lines between video and image formats are increasingly blurring, and the technical distinction between image and video is becoming less clear. This is a good thing, as the distinction between "image" (as in JPG), live recording (iPhone, Android), and image sequence (GIF) is also becoming increasingly blurred. What do we still define as a photo, what as a movie, and what as an image sequence? HEIF files support all these formats and can also contain thumbnails for previews, depth maps, alpha channels, and HDR metadata.

In practice, the .heif file extension is relatively rare; most files appear as .HEIC. The "C" in the file extension is intended to indicate the use of the HEVC codec. The second most common extension is .AVIF—here, AV1 is used as the codec. However, if the codec or other content is unclear, the .heif file extension is preferable.

History of the HEIF Format

The development of HEIF stems from the technical limitations of JPEG. Although the JPEG format, released in 1992, is still by far the most widely used format, the numerous attempts to modernize it (JP2, JXL, JPEG-XR, …) never achieved a real breakthrough. With increasing demands and HDR content, a format was needed that could represent more than 8 bits of color depth per channel with good compression. HEIF provides the framework for this, while the actual implementation is handled by the codec, currently mostly AV1 or HEVC.

Sources

ISO/IEC 23008-12:2025 – Information technology – MPEG media transport – Part 12: Image File Format
Nokia Technologies: "HEIF – High Efficiency Image File Format"
MPEG-H Part 12 – Image File Format

Last updated on 19. March 2026 by Sören with the experience of more than 127,998,035 converted files since 2013.