Apple has just released iOS 11, and one major change is the way recent iOS devices (iPhone 6s and later) store photos. Apple has adopted HEIF (High Efficiency Image Format), which creates photos that take up less space than JPEGs. This is great for the storage on your iOS device, and for your mobile bandwidth, if you sync your photos to iCloud Photo Library.
However, most image editors don't yet support Apple's flavour of the HEIF format (.HEIC files), and Windows 10 does not support it at all. So if you have HEIC files, you may want, or even need to convert them to JPEGs.
The simplest way to do this is to use the free iMazing HEIC Converter app. For now, it's simply the only free solution available that can convert HEIC files to JPEGs without requiring you to upload your photos online.
Here's how to convert HEIC files to JPEGs using iMazing HEIC Converter:
You can download iMazing HEIC Converter here. After you've copied the app from its disk image, launch iMazing HEIC Converter.
Drag files or folders onto the app's window.
Click Convert in iMazing HEIC Converter, and choose a target location to save the JPEG files. Your files will be converted. This may take a while if you are converting a lot of files. iMazing HEIC Converter shows you the progress of the conversion process. When it's finished, you'll have JPEG files that are more compatible.
In most cases, if you need to convert HEIC files, you are probably exporting photos from your iPhone directly with a third-party app. iMazing is a great way to do this, since it offers automatic conversion of HEIC files to JPEG.
Read more about HEIC files in this article.