What is HEIC?

HEIC (High Efficiency Image Container) is the file format iPhones have used to save photos since 2017. It stores the same photo in roughly half the space of a JPG, which is why Apple adopted it, and it is poorly supported outside Apple devices, which is why you are probably reading this page.

Where HEIC came from

HEIC is Apple's implementation of HEIF (High Efficiency Image File Format), a standard published by the MPEG group in 2015 as ISO/IEC 23008-12. The compression inside is HEVC, the same codec used for 4K video, applied to still images. Apple switched iPhones to HEIC by default with iOS 11 in September 2017. The motivation was storage arithmetic: a camera roll of ten thousand photos takes half the space, and iCloud backups halve with it.

What a HEIC file actually contains

Container is the key word. A single .heic file can hold the main photo, a thumbnail, EXIF metadata (location, camera settings, orientation), depth maps used for Portrait mode, and even multiple frames, which is how Live Photos and burst shots are stored. When you convert a HEIC to another format, you are extracting the main image from that container and re-encoding it.

The compatibility problem

Apple devices, and effectively nothing else, treat HEIC as a first-class citizen. Windows requires a paid HEVC codec extension from the Microsoft Store to open HEIC files. Most websites' upload forms reject them. Older Android devices cannot open them, and AI tools like ChatGPT refuse them as attachments. The format is technically excellent and socially awkward: HEVC's patent licensing has kept free software and web browsers from adopting it, with Safari the only browser that displays HEIC, per caniuse.com.

What to do with HEIC files

If the photos stay inside the Apple ecosystem, do nothing: HEIC is the best format for that world. The moment a photo needs to leave, convert it. HEIC to JPG for universal compatibility, HEIC to PNG for lossless editing, HEIC to WebP for your own website, or HEIC to PDF for document portals. All four run in your browser without uploading the photo anywhere.

You can also stop iPhones from producing HEIC in the first place: Settings, Camera, Formats, then choose "Most Compatible", which switches capture to JPG at the cost of roughly double the storage per photo, as documented in Apple's support article.