Why convert HEIC to JPG
HEIC files get in the way when Windows, Android apps, browsers and most websites cannot open them. JPG is the one format every app, website form, printer and email client accepts.
HEIC and JPG compared
HEIC is the format iPhones have saved photos in since iOS 11. It is compact, but outside Apple devices little can open it: Windows needs an extension, and Chrome, Edge and Firefox cannot display it.
JPG (JPEG) is the photo format of the last thirty years: lossy, no transparency, and accepted by every program, website, printer and email client.
What changes in the conversion
JPG is compressed with a quality setting (80% by default) - lower it for smaller files, raise it for more detail.
Private by design
The HEIC decoding and the conversion run in your browser, so your images never leave your device. For other formats use the image converter; to hit a file size such as 100 KB, the image compressor.