I enjoy Apple's notification center, but sometimes I get way too many notifications. This can be distracting, not to mention it takes up screen real estate for quite a while. To my knowledge, there is no way to change the duration of notifications in System Preferences, but it can be done using the defaults command.
You can open Terminal by using Finder and going to Applications > Utilities > Terminal. Or you can hit cmd + space bar and search for Terminal.
Type the following into Terminal:
John
defaults write com.apple.notificationcenterui bannerTime -int {duration}Substitute {duration} for your desired duration. Since I wanted to shorten the duration of the notifications dramatically I used:
defaults write com.apple.notificationcenterui bannerTime -int 1In order for this change to take effect you must log out and back in. Click on the "Apple" in the top left of the screen and click "Log out ...". Or you can type cmd + shift + Q.
If you'd like to test out the notification duration, you can run the following command in Terminal to display notifications from the command line:
osascript -e 'display notification "test notification!"'In this guide, we're going to use AppleScript and a tool called osascript to display macOS notifications.