HEIC explained: from the format itself to converting it

What HEIC actually is

HEIC stands for High Efficiency Image Container — and the important word is container, not format. The standard behind it is HEIF (High Efficiency Image File Format, ISO/IEC 23008-12). Apple adopted it as the default camera format starting with iOS 11, and the files carry a .heic extension.

The container point matters. HEIF is only a wrapper; what determines quality and file size is the codec inside. Nearly all iPhone photos use HEVC (H.265) — the same compression used for 4K video, applied to a single frame. Some newer models use an HEVC variant to store HDR photos.

A single .heic file can hold more than one image. Alongside the main picture it can carry a thumbnail, a depth map (the distance data from Portrait mode), and auxiliary images such as an HDR gain map. That is the fundamental difference from JPG: a JPG is one flat image, while a HEIC is a small package of related images.

Why iPhone switched to HEIC

The motive is storage. At comparable visual quality, HEVC compresses roughly 40% to 50% better than JPEG — which means a HEIC file is often about half the size of the equivalent JPG.

On a 128GB phone that adds up. At an average of 3MB per photo, JPG would hold roughly 40,000 shots in the same space where HEIC fits about 80,000. There was a second motive too: Apple already had hardware HEVC encoders for 4K 60fps video, so reusing them for still photos cost nothing extra.

The price is compatibility. HEVC carries a large patent portfolio, so the codec cannot simply be bundled into every piece of software for free. On top of that, the HEIF container is considerably more complex to parse than JPG. Plenty of older software simply never supported it — and that is the root of the can't-open problem.

Where HEIC runs into trouble

In practice the breakages cluster into a few situations:

• Windows PCs — the built-in Photos app does not understand HEIC out of the box and just reports that the file format isn't supported. A separate codec extension is required.
• Web browsers — Chrome, Edge and Firefox cannot display HEIC directly. Dragging a .heic into a web page, or previewing one in a web app, usually gives a blank frame or a broken image icon.
• Older software — earlier versions of Photoshop, Office, and a long tail of small image utilities.
• Any upload form — passport photo tools, expense systems, application portals. They almost always accept only .jpg or .png and reject HEIC outright.
• Sending photos to someone on Android or an older PC — the recipient most likely cannot open them.

Inside Apple's own ecosystem, none of this applies: Photos, Preview and Finder on iOS, iPadOS and macOS all handle HEIC natively, and AirDrop transfers it as-is.

Platform support at a glance

In one line: seamless inside Apple's ecosystem, a gamble outside it. That is why the demand for HEIC to JPG conversion never goes away.

Three routes to a JPG

There are three ways to turn HEIC into JPG. They trade off differently, and picking the wrong one costs you time.

1. Change the setting and shoot JPG from now on

On iPhone, Settings → Camera → Formats offers a Most Compatible option that makes the camera output JPG directly, so no HEIC ever gets created. The cost is that the same number of photos takes up nearly twice the space, and video drops to H.264 as well. Sensible if your photos mostly travel between phone and Windows. Steps are in how to disable HEIC on iPhone.

2. Convert in the browser

Open an online converter, drop in the .heic, download a .jpg. It is the least effort — but there is one thing worth checking: many online converters upload your photos to their own servers to do the work. Photos usually carry EXIF data including where and when they were taken, and uploading hands all of that over.

This site works differently: decoding and encoding both happen inside your browser, the photos never leave your machine, and it still works offline. The mechanism is described on the about page.

3. Use built-in or command-line tools

On a Mac, sips converts in batches with a single command. On Windows, once the HEIF extension is installed, the Photos app can save individual files as JPG. If you are handling hundreds of photos and would rather not install anything, this route is more dependable. The exact commands are in opening HEIC on a Mac.

Keep HEIC or convert to JPG?

There is no universal answer — it depends on who the photo goes to next:

• Stored on your phone for your own viewing — keep HEIC. Half the space, better quality, and no reason to convert.
• Sent to other people, uploaded to a portal, edited in older software — convert to JPG. Compatibility wins, and the quality difference is not visible to the eye.
• Long-term archiving — keep the original HEIC and export a JPG alongside it, rather than deleting the HEIC and keeping only the JPG. JPG is lossy, and repeated editing degrades it further each time.

As for how much quality a JPG conversion actually costs, we measured it on our own pipeline across several quality settings — see the HEIC to JPG quality measurements.