Your iPhone saves photos in a format half of the internet cannot read. Here is what HEIC is, why Apple chose it, how to convert safely, and how to stop your phone creating them.
You email a photo from your iPhone to a colleague and they reply that they cannot open it. You upload a picture to a job application form and it is rejected. You copy holiday photos to a Windows laptop and every one shows a blank icon. The culprit is a four-letter file extension most people have never deliberately chosen: .heic.
What HEIC actually is
HEIC stands for High Efficiency Image Container. Apple switched to it as the default camera format in iOS 11, released in 2017, and every iPhone since has used it unless you changed a setting you probably did not know existed.
Technically it is an excellent format. It stores an image at roughly half the file size of an equivalent JPG with no visible quality loss, supports 16-bit colour where JPG manages 8, handles transparency, and can hold multiple images in one file — which is how Live Photos work. On a phone holding thousands of pictures, halving the storage is a genuine benefit.
So why can nothing open it?
Because excellence and ubiquity are different things. JPG has been universally supported since 1992. HEIC arrived in 2017 encumbered by patent licensing, which made other vendors slow to adopt it.
The result is a long tail of software that simply does not know what to do with your photos: older Windows installations without the paid HEIF extension, many Android devices, a great many web upload forms, older versions of Photoshop and Office, most email clients when previewing attachments, and a surprising number of print services.
Converting to JPG trades some file size for the certainty that the image will open anywhere.
The privacy problem with online converters
Search for a HEIC converter and you will find dozens of free sites. Nearly all of them work the same way: you upload your photograph to their server, it is converted there, and you download the result.
For holiday snaps that may be acceptable. It is worth understanding exactly what you are sending, though, because a photograph is not only an image. Embedded in the EXIF metadata of almost every iPhone photo is:
- The exact GPS latitude and longitude where it was taken
- The date and time, to the second
- The device model and its unique camera characteristics
- Often the orientation, altitude and compass direction
Upload a batch of family photos and you have transmitted a precise record of where you live, where your children go to school, and when you were away from home. That is a meaningfully different transaction from "convert my file."
A browser-based converter avoids the question entirely: the decoding happens on your own device and nothing is transmitted.
Choosing an output format
Converting from HEIC, you have three sensible destinations:
- JPG — the default choice. Universally readable, small, ideal for sharing, printing, email attachments and upload forms.
- PNG — lossless, so nothing degrades if you intend to edit and re-save repeatedly. Files are considerably larger. Choose it for graphics work, not for sharing.
- WEBP — the smallest files at comparable quality, and well supported by modern browsers. Ideal if the photos are destined for a website.
On quality settings, 90% is visually indistinguishable from the original for essentially all photographs. Drop towards 70% only when you are fighting a hard upload limit.
How to stop your iPhone making HEIC files
If the compatibility friction is not worth the storage saving, switch the camera back to JPG:
- Open Settings
- Tap Camera
- Tap Formats
- Select Most Compatible
From then on new photos are captured as JPG. Note that this changes nothing about photos you have already taken — those stay HEIC and still need converting.
There is a second setting worth knowing. Under Settings → Photos, scrolling to the bottom reveals Transfer to Mac or PC. Setting this to Automatic makes your iPhone convert photos to JPG as it transfers them over a cable. Set to Keep Originals, it sends the raw HEIC.
Converting a whole camera roll
Converting photos one at a time is miserable. Any tool worth using handles batches — select hundreds of files, convert them in one pass, and receive a single ZIP.
Our HEIC to JPG converter does this entirely inside your browser using a WebAssembly build of libheif. Your photographs and the location data inside them never leave your device, there is no file count limit, and no account is required.
Once converted, you might also want to combine the images into a single PDF for sharing or filing.
Pixellwork Editorial
Documents & Privacy
Published October 12, 2026