If you have an iMac from 2009 or later, it can be used as an extra display when attached to another Mac (such as a laptop). Both Macs must have a Thunderbolt or Mini DisplayPort, and you’ll need a Thunderbolt cable to connect them.
When you use the iMac as a display, any apps you have running on the iMac will continue to run in the background. You just won’t see the iMac’s desktop or apps because its display will be showing the apps from the other Mac.
While this setup works, it may not be ideal for long-term use. The iMac uses much more power and is more prone to wearing out than a standard display. And the iMac must be in good working order – able to start up and operate normally. Standard displays are less expensive than they were in the past so in many cases you could sell the iMac and have enough money to purchase a new display.
Using an iMac as a display for another Mac
- Turn on both computers. Neither computer should go to sleep while you’re using them.
- Connect a ThunderBolt cable to each computer.
- Press Command-F2 on the iMac’s keyboard (the one used as a display).
- To see the iMac’s desktop and apps again, press Command-F2 on the iMac’s keyboard.
