Kept / Glossary

HEIC

HEIC is the format an iPhone saves photos in by default: a still image compressed with HEVC and wrapped in Apple’s High Efficiency Image container. It stores roughly the same picture as a JPEG in about half the space, which is why Apple made it the camera’s default in iOS 11.

Updated: September 2026 · Kept

What it costs you in storage

A 12 MP HEIC frame from an iPhone camera usually lands between 1.5 and 2.5 MB. The same shot saved as JPEG is roughly double that. Over a library of tens of thousands of photos, the format you shoot in is the difference between a collection that fits on the phone and one that doesn’t — without a single photo looking any different.

The catch is that HEIC only applies to what the camera writes. Images that arrive from messaging apps, screenshots and anything downloaded from the web come in at whatever size the sender or the app chose, and those often outnumber your own camera shots.

What you can change in iOS

The switch is Settings › Camera › Formats:

  • High Efficiency — HEIC for photos, HEVC for video. The default, and the smaller one.
  • Most Compatible — JPEG for photos, H.264 for video. Roughly doubles the size of every new photo you take.

Switching does nothing to the photos already in your library; it only changes what the camera writes from that point on. Compatibility is rarely a reason to switch, either — when you share a HEIC out of Photos, iOS converts it for you, and Settings › Photos › Transfer to Mac or PC set to Automatic does the same when you plug the phone in.

Why the format is not where your space went

HEIC is already the efficient option, so there is no saving left to make there. The weight in a large library sits somewhere else: runs of near-identical frames, Live Photo video attached to every still, screenshots nobody ever deletes, and a handful of very long videos. Those are worth attacking; the file format is not.

Kept reads your library on the phone itself — the photos are never uploaded to be analysed anywhere.

Also asked

Does switching to Most Compatible convert the photos I already have?
No. The Formats setting only decides what the camera writes from that moment on. Photos already saved as HEIC stay HEIC, and nothing in your library is re-encoded or re-sized when you flip the switch.
Will HEIC photos open on Windows or Android?
Usually yes, and where they do not, iOS converts on the way out. Sharing a HEIC from Photos hands over a JPEG in most cases, and Settings › Photos › Transfer to Mac or PC set to Automatic converts when you connect the phone by cable.