Where is the convert command in macOS?
There is no command/utility named convert built into macOS.

convert utility is installed as part of ImageMagick. You can easily install ImageMagick using Homebrew by running:

brew install imagemagick


To install Homebrew, run:

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"