Right-click or Control-click on the app’s icon in the Dock and choose Force Quit.If you can access the Apple menu, click on it, choose Force Quit, select the app and press Force Quit.Press Command-Option-Escape, select the app from the box that opens, and press Force Quit.There are several different ways to force quit an application. However, it can be useful, despite the risk of losing data, if the app in question hangs and fails to respond for several minutes, and especially if it causes the rest of your Mac to hang or even just slow down. It tells the app to stop what it’s doing immediately and not to display any of the dialogs it might usually show you before it closes. Force quitting an application is a pretty drastic course of action.
