The Notification Center came to OS X in version 10.8, and has been a very welcome addition to the operating system ever since. Thanks to this carryover from iOS you can see banner notifications in the top corner of your screen, letting you know anything from comments on social media, software updates, to new emails.
The banners that appear often clear themselves too quickly and while you can open the Notification Center to see the cleared messages, it would be better if the Notification Banners themselves persisted for a little more time. You can actually make these banners persist for as long as you want, as long as you don’t mind copying and pasting a defaults write command into Terminal. It’s not as hard as you think, and here’s how you do it.
If you already have Notification Center set up how you like, skip the next section and jump to Notification Banners below it.
Before you start changing how long banner notifications show for, you should probably check on what comes up as a banner and what doesn’t. To do this head over to System Preferences (Apple Menu > System Preferences) and click on Notifications.