Since iOS 11, iPhones have saved photos in HEIC format by default. HEIC — High Efficiency Image Format — is a great format: it produces images with approximately half the file size of equivalent JPEGs maintaining excellent visual quality.
Yet there is a major problem. HEIC is an Apple-centric format not universally accepted beyond the Apple ecosystem. Windows PCs, non-Apple phones and many websites cannot open HEIC photos lacking extra apps.
Converting HEIC to JPG is the critical process that makes iPhone images compatible everywhere. Common scenarios where this becomes a problem involve sharing photos to non-Apple users, adding images to websites incompatible with HEIC.
People with Macs have the easiest method. Open the HEIC photo in Preview, go to File, then Export and pick JPEG as the format.
Windows more info PC users, web-based converters process HEIC to JPG conversion requiring no software installation. Select the HEIC file and save the converted JPG.
Try alljpgconverters.com offering a totally free browser-based HEIC to JPG tool with no account necessary.