Use the setting in the log out or restart dialogue
When you log out of your Mac or restart it, deselect ”Reopen windows when logging back in” when prompted.
Or start up in safe mode, then restart normally. This doesn't change the setting, but your Mac forgets any windows that were open the last time you logged out or restarted.
If you deselect this setting and an app continues to open automatically:
- The app might be a login item. You can add or remove login items in Users & Groups preferences.
- The app might have installed its own startup software. Often this is controlled by a setting within the app. Check the app's preferences or documentation, or contact the app's developer.
Use the setting in General preferences
To prevent apps from remembering the windows they had open, choose Apple menu > System Preferences, click General, then select ”Close windows when quitting an app”.
Or press and hold the Shift key while opening an app. This doesn't change the setting, but the app forgets any windows that were open the last time you quit the app.
If these steps don't work for an app, the app might have its own setting for reopening windows. Check the app's preferences or documentation, or contact the app's developer.