HEIC
Also known as: HEIF, High Efficiency image format, heic file
HEIC is the file format iPhones use to save photos by default. It stores the same image quality as JPEG in roughly half the space using HEIF compression, which is why switching away from it makes your library larger.
- iPhone default photo format since iOS 11
- About half the size of JPEG at the same quality
- Switching to JPEG increases library size
Why iPhone uses HEIC
Since iOS 11, iPhones capture in High Efficiency (HEIC/HEIF) instead of JPEG. The format is more modern and far more space-efficient, so a typical photo is about half the size with no visible loss in quality.
You can switch to JPEG under Settings > Camera > Formats > Most Compatible, but expect your camera roll to grow noticeably, since JPEG files are larger.
Compatibility
Modern Apple devices, Windows 11, and most current software open HEIC natively. When you share a HEIC photo to an app or device that cannot read it, iOS usually converts it to JPEG automatically.