The short answer: storage
A 12-megapixel iPhone photo saved as JPG is 2–4 MB. The same photo saved as HEIC is 1–2 MB. Multiply that by every photo in a typical user's library and the saving runs into tens of gigabytes — saving Apple iCloud storage costs and giving users more headroom on their phone. HEIC also keeps richer image data (10-bit color, depth maps, Live Photos) that legacy JPG simply can't represent.
Why HEIC compresses so much better
HEIC uses HEVC (H.265) — the same codec used for high-end video — to compress still images. HEVC is a generation newer than the JPEG algorithm (DCT-based, designed in 1992) and includes advanced techniques like intra-prediction, larger transform blocks, and adaptive entropy coding. The result is that HEIC reaches about the same perceptual quality as JPG at half the bytes.
The trade-off: compatibility
HEIC works flawlessly inside Apple's ecosystem and quietly converts to JPG when you AirDrop or share to an app Apple knows can't handle it. The friction is when you bypass that fallback — emailing a HEIC directly, uploading to a website's file picker, or transferring photos to a Windows or Android device. Those flows show "unsupported format" errors that confuse non-technical users.
How to make your iPhone save JPG instead
Open Settings → Camera → Formats and change the selector from "High Efficiency" to "Most Compatible". From that point on, every new photo you take is saved as JPG (and every video is saved as H.264 instead of HEVC). Photos already in your library remain HEIC; switching the format setting only affects new captures.
Should you switch?
For most people, no. The smarter workflow is to leave HEIC enabled and convert to JPG only when you need to share with a non-Apple recipient. Converter.Plus does this in a single drag-and-drop, with no upload — your photos never leave your device. If you frequently hand off raw photos to clients, collaborators, or printers who don't accept HEIC, switching to "Most Compatible" is reasonable; just be aware your photo library will grow roughly twice as fast.
Frequently asked questions
If I switch to JPG, will old HEIC photos convert too?
No. The setting only affects photos you take after switching. Existing HEIC photos remain HEIC. Use Converter.Plus to convert them in batch when you need to.
Does AirDrop convert HEIC automatically?
AirDrop preserves the HEIC original between Apple devices. When you share to a non-Apple recipient or to an app like Mail, iOS automatically transcodes to JPG before sending if the recipient or app can't read HEIC.