About HEIC/HEIF (High Efficiency Image Format)
HEIC is the file extension Apple uses for photos stored in HEIF, the High Efficiency Image Format. Under the hood it compresses images with HEVC (H.265) video technology, which is why an iPhone photo saved as HEIC is often about half the size of the same shot as a JPEG. Apple made it the default camera format in iOS 11, so nearly every photo taken on an iPhone since 2017 is a HEIC file.
The catch is compatibility. Windows needs a paid codec to open HEIC, plenty of websites and upload forms reject it, and older software does not recognize it at all. In practice, HEIC is a format you convert away from far more often than you convert into.
Convertmaxxing reads HEIC and converts it to JPG, PNG, WebP, and other formats entirely in your browser — your photos never leave your device. One important limit: conversion is one-way. This tool can open and decode HEIC files, but it cannot create them.
Strengths
- Very efficient — photos are often roughly half the size of an equivalent JPEG
- Supports 10-bit color and wide color gamuts, which JPEG cannot match
- Can hold extras like depth maps and Live Photo data in a single container
- The no-effort default on iPhone — it just happens when you take a photo
Limitations
- Poorly supported outside Apple devices — Windows, Android, and many web forms struggle with it
- This converter can read HEIC but cannot create it — conversion is decode-only
- A risky choice for sharing, since recipients often cannot open the file
- Built on patent-encumbered HEVC compression, which is why broad support never arrived