*.heic, so this is not a desired and wildly available extension, that someone on the other side would like to see.imagemagic on your computer (it's free and available on all platforms). If you like my editing, especially the heic type of images, you may need to install an additional library called libheif. For other platforms use alternative.brew install libheif imagemagick parallelmagick mogrify -format jpg -quality 60 *.HEICmagick mogrify ..., just mogrify ..., because after the installation of imagemagic, all its sub-programs should be available for you directly in the command line.png is different then PNG). The extension-case may be different then in the command you will see in the examples here.mogrify program use only 1 CPU at the time. If you have a lot of pictures to convert, you may want to utilize more of your CPUs with GNU parallel.parallel, and if you execute it, the conversion should happen much faster.parallel magick mogrify -format jpg -quality 60 ::: *.HEICimagemagic secrets! It's definitely extremely helpful software.