Why iPhone Photos Are HEIC and How to Convert Them

If you've ever AirDropped a photo from your iPhone to a Windows machine, dragged it into a web form, or emailed it to someone on Android, you've probably hit this:

"This file format is not supported."

The file is .heic. Almost nobody on the receiving end can open it without extra software. So why does Apple ship it as the default?

This post explains what HEIC is, why iPhone uses it, when to keep it, and how to convert it without uploading your photos to a stranger's server.

What HEIC actually is

HEIC stands for High Efficiency Image Container. It's a wrapper format defined by the HEIF standard (ISO/IEC 23008-12), and inside the wrapper Apple stores image data encoded with HEVC, the same video codec your phone uses for 4K recordings.

That's the whole trick: HEVC is a really good compressor. Apple realized that if you take one frame of HEVC video and call it a still image, you get a JPG-equivalent photo at roughly half the file size, with better color depth and support for things like Live Photos and depth maps.

A typical iPhone photo:

• JPG: ~3.5 MB
• HEIC: ~1.7 MB

For a phone with thousands of photos, that's tens of gigabytes saved.

Why nobody else can open it

HEVC is patented. The patent pool around it is famously messy: multiple licensors, ongoing litigation, royalties owed by anyone who ships a decoder. Apple paid for a license. Most browsers, most Linux distributions, and lots of Android devices haven't.

The result: HEIC files render fine on iPhone, Mac, modern Windows (with the optional HEIF extension), and not much else. Web browsers don't support HEIC natively even in 2026. You can't drop a .heic into a <img> tag and expect it to render.

This is why every contact form, every employer's HR portal, every "upload your ID" page rejects HEIC. They're using browser-native rendering, and browsers don't speak HEVC.

When to keep HEIC

If the photo is staying on your iPhone, leave it as HEIC. It's smaller. iCloud Photos and iMessage handle conversion automatically when needed.

If you AirDrop between Apple devices, HEIC is fine. macOS, iOS, and iPadOS all natively read it.

If you're saving photos to your own NAS or hard drive and you only ever view them on Apple devices, also fine.

When to convert HEIC to JPG

Anywhere the file leaves Apple's ecosystem:

• Uploading to a website that doesn't support HEIC, most of them.
• Sending to someone on Windows or Android.
• Embedding in a document, slideshow, or design tool that hasn't added HEIF support.
• Posting to a forum or community where you don't control the rendering pipeline.
• Editing in older photo software.

You'll lose the file-size advantage, but JPG works everywhere.

How to convert without uploading

The standard advice, "upload your HEIC to a converter site", is bad advice. You're handing your photos to an unknown server. Even if the site claims to delete them, you have no way to verify it. Photo metadata often includes GPS coordinates and timestamps. The risk-to-reward ratio is bad.

The better approach: convert in your own browser, where the file never leaves your device.

This works because modern browsers can run WebAssembly. You can ship a HEIC decoder (the open-source libheif) compiled to WASM, decode the file in the browser tab, and re-encode it as JPG using the browser's built-in encoder. The file lives in JavaScript memory for a few seconds and never touches a network connection.

OmegaPix's HEIC to JPG converter does exactly this. Drop a HEIC (or fifty), it converts them in your browser, you download the JPGs.

Avoiding the problem in the first place

If you don't want to convert every photo individually, change your iPhone's setting:

Settings → Camera → Formats → Most Compatible

This makes the iPhone shoot JPG and H.264 video instead of HEIC and HEVC. You give up the file-size savings, but every photo from that point on is universally compatible.

The hybrid setting: leave the camera on HEIC for the savings, but turn on Settings → Photos → Transfer to Mac or PC: Automatic. iOS will convert HEIC to JPG on the way out when you copy to a non-Apple device. (This setting only works for USB transfers, not AirDrop or web uploads.)

A note on quality

HEIC at default iPhone settings is a 10-bit, slightly higher-quality source than the JPG it converts to. The JPG output is 8-bit and slightly more compressed by default. For most viewing (phone screens, web galleries, social media) the difference is invisible. If you're producing prints or doing color-critical work, keep the HEIC original and convert only the copy you're sharing.