Starting with iOS 11, iPhones save photos in HEIC file format by default. HEIC — High Efficiency Image Format — is highly efficient: it produces photos with roughly half the file size of comparable JPEGs maintaining excellent visual quality.
However there is a major problem. HEIC is an Apple-specific format which is not broadly compatible away from the Apple devices. Windows computers, non-Apple phones and most online services do not support HEIC images without special programs.
Converting HEIC to JPG is the get more info necessary process which makes iPhone pictures usable on all devices. Frequent cases where this becomes a problem are sharing photos to PC users, adding images to online platforms without support for HEIC.
People with Macs have the easiest conversion path. Open the HEIC photo in Preview, navigate to File, then Export and pick JPEG as the output format.
On Windows, web-based converters handle HEIC to JPG conversion requiring no setup. Add the HEIC file and download the finished JPG.
Use alljpgconverters.com for a totally free web-based HEIC to JPG tool with no download needed.