How to Lock Your Mac Without Turning Off the Screen

After you lock a Mac, the display turns off about 30 seconds later. No setting changes that. To keep the display on, run caffeinate -d -i before you lock. To show your desktop instead of the login window, use a cover app like Dimma Screen.
Tested on macOS 27.0, October 2026.
The "Turn display off" setting in System Settings › Lock Screen doesn't change the 30 seconds.
Locking doesn't stop your apps. Sleep does. To keep the Mac from sleeping while it's locked:
More in how to keep your Mac awake and what locking does to AI agents.
The login window tells everyone walking by that you're gone. So does a dark screen.
Dimma Screen is a menu bar app that covers every display with a tint you can barely see. Your desktop stays lit and keeps moving. Touch a key or the mouse, and it asks for your PIN.
Dimma Screen · macOS 26 Tahoe or later · Apple silicon · All features free for 3 days, then $9.90 once. No subscription.
macOS turns the display off about 30 seconds after you lock, whatever your "Turn display off" setting is. System Settings has no option to change it.
Not in System Settings. Run caffeinate -d -i in Terminal before you lock. In our test on macOS 27.0, the display was still on 2½ minutes after locking.
Locking doesn't stop your apps. Sleep does. To keep downloads going while the Mac is locked, run caffeinate -i in Terminal before you lock.
No. The macOS lock screen always shows the login window. A cover app like Dimma Screen leaves your desktop visible under a faint tint and asks for a PIN instead.
A screen that shows the login window is still locked, so keeping it on is fine. A cover app keeps people nearby off your screen, but it isn't a security lock. Where you need real security, press Control-Command-Q.