The consensus is that iMacs are the crown jewel of desktop computers, but the trend is what it is: people are turning more to laptops to be able to move around with their computer. And in this case, the best thing to do at home is to connect it to a monitor.
But what happens when you don’t have a screen at home but a Mac at work? Well, there are also ways to use this mac as an external monitor. Let’s see the means at our disposal to achieve this.
What models of Mac can become an external monitor
Not every Mac can be used as an external monitor for another Mac, and there are two different ways to do this. If you want to do it with AirPlay, you must have one of the following Macs as a “receiver”:
- MacBook Pro or MacBook Air from 2018 and later, including the MacBook Air M2
- iMac from 2019 or later, including the Mac mini M1
- iMac Pro 2017
- mac pro 2019
- Mac mini M1 and Mac mini M2 or M2 Pro (with a monitor attached, of course)
If, on the other hand, you want to use a cable to connect your Mac to that other Mac you want to use as a monitor, the requirements are even higher because you can only use certain older iMacs:
- 2009 and 2010 24-inch and 27-inch iMac with macOS High Sierra installed
- iMac 2011, 2012, 2013 and Mid 2014 with macOS High Sierra installed
In this case, you will also need a Thunderbolt cable of the version of Macs you are using (Thunderbolt 1 or Thunderbolt 2), or a miniDisplayPort cable if we are talking about 2009 or 2010 Macs. In any case, the Mac you use to extend your desktop must be a 2019 Mac and you must have macOS Catalina or later installed.
How to turn a modern Mac into an external monitor
In this case, we can use AirPlay to be able to “send” a second monitor to another Mac. We just have to open both computers under the same Wi-Fi network (if we have it connected by cable, it also works), and on the Mac we want to use, look for the ‘Mirror Screen’ option in the Control Center:
You’ll see that after a few seconds the other Mac will mirror the first one’s screen and you’ll have an icon in the menu bar telling you so. If you tap on it, you will see that you will have the option to clone the main Mac screen or extend the desktop:
How to convert an old iMac with an external monitor
If you want to connect one of the older iMacs mentioned above, just turn on both computers and connect to their corresponding systems. Then join them via their miniDisplayPort or Thunderbolt 1 or 2 connections and press CMD + F2 keys on old iMac. You will see how the iMac suddenly shows the desktop of the other computer.
To be able to reverse this and get the original desktop back from the old iMac, just press CMD+F2 again.
