Many people that encounter .heif to .heic files for the first ime wonder how to open them on their Windows machines or convert them to some common format like JPEG (.jpg, .jpeg). It should be pretty easy to convert HEIC format on Mac, HEIF format is somewhat troublesome on certain versions of Windows. If your machine does not support HEIF/HEIC format you, you will have to use one of the dedicated converters, like the free iMazing HEIC converter.
Open HEIC file Open JPG fileA hungarian software solution
A free converter for macOS/OS X HEIC images