The Screen Blackout
By default, macOS is aggressively tuned to save battery power and preserve the lifespan of your screen. If you step away from your Mac, or if you simply stop moving the mouse and typing for a few minutes (e.g., while reading a long document or watching a video that isn’t using a native media player), your Mac will automatically dim the screen and then put the display completely to sleep, turning it pitch black.
While this is great for battery life on a MacBook, it is highly frustrating on a desktop Mac (like an iMac or Mac Studio) plugged into the wall, especially if you use your computer to reference notes while working at your desk or to display a dashboard. You can stop your Mac from automatically turning off its screen.
How to Prevent Your Mac Display from Sleeping
You can adjust the display timeout settings in your Mac’s Lock Screen preferences.
- Click the Apple Logo in the top-left corner of your screen and select System Settings… (or System Preferences on older macOS versions).
- Scroll down the left-hand sidebar and click on Lock Screen (On older versions, this is located under Energy Saver or Battery).
- Look for the dropdown menu labelled “Turn display off on power adapter when inactive.” (If you are on a laptop, you will also see a separate option for “on battery”).
- Click the dropdown menu and change the timer (which might be set to 10 or 15 minutes) all the way down to Never.
- A popup warning may appear telling you that keeping the display on permanently uses more energy and may reduce the life of the display. Click OK to confirm your choice.
Your Mac’s screen will now stay brilliantly lit indefinitely, remaining fully visible until you manually lock the screen or put the computer to sleep from the Apple menu.