HEIF File: How to Open, Identify, and Convert It

HEIF is the binary image container standardized as ISO/IEC 23008-12 and based on ISO-BMFF. It can contain one image, an image collection, or a sequence, plus thumbnails, derived or auxiliary images and Exif, XMP, or MPEG-7 metadata.

Use a reader that supports the HEIF container, the compatible brand recorded in the file, and its image codec. Checking only the .heif extension is insufficient because HEIF is a container rather than a single compression method.

Choose a Windows reader that explicitly supports both ISO-BMFF HEIF containers and the codec used by the file. If it still cannot decode the image, open and export it on a compatible Apple device or use another codec-aware converter while retaining the original.

On macOS High Sierra 10.13 or later, open the HEIF image in Photos or Preview. You can then export it as JPEG or PNG, but the export may not retain every image, relationship, color property, or metadata item in the container.

iOS 11 and later include HEIF support. Open the image with a compatible system app; when sharing to an incompatible recipient, the device may automatically provide a JPEG instead.

The reader may understand the HEIF container but lack support for its brand or image codec, or the file may be damaged or mislabeled. Verify the ISO-BMFF box structure and compatible brands instead of relying only on the extension.

HEIF is the general container format. HEIC is a HEIF subtype using particular HEVC brands, so a HEIC file is a kind of HEIF file but not every HEIF file is HEIC.

Export the image through a compatible reader such as Photos or Preview on Mac. JPEG does not preserve the HEIF bitstream or container structure, and a single-image export may omit additional images, thumbnails, relationships, color information, or metadata; keep the original.

Use a converter that explicitly reports which images, color information, and metadata it retains. PNG cannot reproduce the entire HEIF container structure, so confirm the output and preserve the source file even when some metadata is copied.

Do not assume it is safe solely because it has a .heif extension. HEIF is a complex container that may include hidden or protected items and external-media references; inspect untrusted files with an updated, isolated parser and restricted resource access.

PRONOM checks for ASCII ftyp at offset 4 followed by a recognized brand such as mif1, msf1, heic, heix, hevc, or hevx, but this is not a unique fixed full-file magic number. Validate the ISO-BMFF structure and brands. IANA uses image/heif for a general single image or collection; sequences use image/heif-sequence.