Does converting HEIC to JPG lose quality?

Converting HEIC to JPG loses a small amount of detail, because JPG is also a compressed format. At a good quality setting you won't see the difference when viewing or printing the photo.

What does change is the file size. The JPG will usually be bigger than the HEIC it came from, because JPG compresses less efficiently.

In the converter below you can pick Smaller, Balanced or Best. Balanced suits most photos. Choose Best for prints or anything you plan to edit.