How to Kill an Application on a Mac Terminal

On your Mac, you may occasionally encounter an application that becomes unresponsive or causes abnormally high CPU usage and does not respond when you attempt to close it through standard means. If you can open a Terminal session, you can force any application to close using the "kill" command. Use this command to kill an application that does not close when you select the appropriate option on the menu.


Click the "Go" pull-down at the top of the screen, and select "Utilities."


Double-click the "Terminal" icon to start a Terminal session.


Type "top -u" in the Terminal window, and press "Return." This displays a text-based list of all running applications. The "PID" column displays a number next to the name of each application. For example, you might see "128 Safari" on the left side of the window.


Locate the number in the "PID" column for the application you want to kill, and then press the "Q" key to exit the utility and return to the Terminal prompt.


Type "sudo kill -9 128," and press "Return." Replace "128" with the number you located in the previous step.


Type the administrator password for your computer, and press "Return" again. The program closes immediately. Close the Terminal window to return to the desktop.