Image format guides

Explanations of the formats that cause problems, and what to do about them. Written to answer the question rather than to fill a page.

• What is a HEIC file? HEIC is the image format iPhones use by default. It stores photos at about half the size of JPEG. Here is what it is, why Apple uses it, and what it can do that JPEG cannot.
• Why HEIC files won't open on Windows HEIC files fail to open on Windows because the HEVC codec they use is patent-encumbered and Windows does not always include a decoder. Here are the three ways to fix it.
• How to stop your iPhone shooting HEIC Set your iPhone to shoot JPEG instead of HEIC: Settings, Camera, Formats, Most Compatible. Here is what that costs you and the alternative that keeps both.
• HEIC vs JPEG — which should you keep? HEIC files are half the size with better colour and more features. JPEG opens everywhere. Which matters depends entirely on where the photo is going.
• WebP vs AVIF vs JPEG, compared AVIF gives the smallest files, WebP the best balance, JPEG the widest compatibility. Serve all three with a picture element and let the browser choose.

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