HEIC files are a modern image format that Apple started using with iOS 11 and macOS High Sierra. Instead of the old JPEG format, they use a newer compression technology called HEIF (High Efficiency Image Format), which can make photos about half the file size while keeping the same or even better quality.
Since it is very high efficient format of iamge, you can store way more pictures on your iPhone without running out of space, and they still look sharp. It add very advantages like it support cool extras like 16-bit color, transparency, and even storing multiple images in one file (like Live Photos or burst shots).
The downside of HEIC image format is that not every device or program outside the Apple world can open them easily yet, so sometimes you have to convert them to JPEG to share with others.. We have designed this image converter tool easy-to-use. Just upload your HEIC image file and hit Convert. Within a second, your JPG converted image is ready to download.