DiffMerge allows a variety of different command lines formats. These allow DiffMerge to launch with different types of initial windows and to be invoked by other applications. Each usage is summarized in the following sections.

DiffMerge Command Flags/Options have a long and short form and may either be prefixed by a '/' or a '-' depending upon your platform. For example: -h, -help, --help, /h, or /help.

For options that require a value, they must have a COLON, EQUAL, or SPACE separator character between the keyword and the value. And the value should be quoted if it contains spaces or special characters. For example, /caption="Hello World!".

Generally, DiffMerge will exit with 0 status when there are no errors and a 3 status when there is a command line syntax error.