What is HEIC? A Complete Guide to Apple's Image Format

HEIC is based on the HEIF standard (High Efficiency Image Format), developed by the Moving Picture Experts Group — the same organization that created MP3 and MP4. The standard was finalized in 2015, and Apple adopted it for iPhones and iPads with iOS 11 in September 2017.

The "container" in HEIC means the file can hold multiple images, metadata, depth maps, and even short video clips — all in one file. This is how iPhone stores Live Photos (a still + a short video clip) and Portrait mode photos (image + depth data) in a single compact file.

Under the hood, HEIC uses HEVC (H.265) for image compression — the same codec used in 4K video streaming. This is why it achieves such dramatic compression improvements over the 1990s-era JPEG algorithm.

Traditional JPEG uses discrete cosine transform (DCT) — a mathematical technique from the 1970s — to compress images. It divides the image into 8×8 pixel blocks and discards fine detail. This works well but shows visible "artifacts" (blurry edges, color banding) at high compression.

HEVC/HEIC uses a more sophisticated approach with variable block sizes (4×4 up to 64×64 pixels) and advanced prediction algorithms that look at surrounding image data. The result: the same visual quality in roughly half the file size.

For a typical iPhone 15 photo at 12 megapixels:

• HEIC: approximately 3–5 MB
• JPG (equivalent quality): approximately 6–10 MB
• PNG (lossless): approximately 18–30 MB