Apple’s macOS and iOS devices have supported High Efficiency Image File Container (HEIC) images for quite some time now. Such files require about half as much storage space as equivalent quality JPEG files. But if you do need to convert HEIC format images to JPEG, it’s easily done on your Mac — no special software or app needed. Here are two ways to do it:
With the Preview app
Open one or multiple HEIC file(s) in Preview > In the top menu, click File > Export > Format (drop-down menu) > select JPEG.
Additional options: 1) JPEG Quality: Adjust the slider (Higher quality = Larger file), 2) Rename the file if desired.
Specify where you want to save the file > Click Save.
With the Photos app
Open one or multiple HEIC file(s) in Photos > In the top menu, click File > Export > Export ‘N’ Photos > Set the options (Photo type = JPEG; additional options: JPEG Quality, size, file name) > Export > Specify where to save.
A shortcut way to do this, if you don’t want the additional options, is to select the HEIC image(s) in Photos, and drag-and-drop them on to the desktop or a Finder window. This will also convert them to JPEG format.