When an iPhone HEIC photo will not open

iPhones save photos as HEIC by default. It is roughly half the size of JPG at the same quality, but web browsers cannot open it. That applies to Chrome, Firefox, and Edge alike.

Stopping it happening again

• Open Settings on the iPhone.
• Go to Camera.
• Tap Formats.
• Choose Most Compatible instead of High Efficiency.

Every photo taken after that saves as JPG. Files get somewhat larger, and they work everywhere.

Photos you already took

• Simplest: share the photo to yourself over mail or a messaging app. Most convert to JPG on the way.
• On a Mac, open it in Preview and use File then Export to pick JPEG.
• On Windows, install the HEIC extension for the Photos app, then use Save as and choose JPG.