Guide to using iMac as a display for other devices — 2022

There are many users who are looking for the possibility of being more productive and this can happen by having a second screen on the desktop. It may seem silly, but work on two screens It is something tremendously comfortable because we can have several windows open and in our view at the same time. Surely you may think that you will have to spend a lot of money on a secondary screen for this, but the truth is that some iMac models also have an external screen thanks to the ‘target screen’ function . In this article we explain what it is and also how you can activate it.

It is not possible to do it on all iMacs

It may seem absurd that the latest Apple desktops don't have this capability, but it's true. The iMac with retina display cannot be used for this purpose due to some kind of hardware limitation that they have and that Apple itself has never commented on. That is why the list of devices that can serve as an external monitor is reduced, having the following equipment.

  • 27-inch iMac from late 2009 to mid 2010.
  • iMac from mid 2011 to mid 2014.

It should be noted that in addition to being one of those models, iMacs must meet another requirement. In the case of the first outstanding models, they must have mini DisplayPort display that allows them to be connected, while the others must have Thunderbolt port . We remember that, when they were for sale, not all of them came with those ports and, therefore, you must make sure that yours does.

In this case, it is impossible to obtain these desktop computers officially in an authorized Apple store. This is because most of them are models that are discontinued. But if you still want to opt to have an iMac as a secondary screen, you'll be able to access the second-hand market to get a model that someone else doesn't want. Although you will also have to check that it meets all the requirements that we have previously mentioned. Above all, we must emphasize the rear port that will be in charge of transferring the image information.

How to make them serve as an external screen

As we saw, we have two different types of iMacs that support this functionality through two different ports. Although the steps to follow in both cases are practically identical, the truth is that it is convenient to differentiate some points to take into account when carrying out the process, something that we will explain in the following sections.

On iMacs with a Thunderbolt port

If you have an iMac with a Thunderbolt port, you can connect it to any other Mac o PC Windows that also has this type of port. To be able to identify if this is your case, you should look for it to have a USB-C port with a small lightning bolt next to it silk-screened. If this is your case, now you must have in your possession a cable that has a Thunderbolt connection at both ends.

Once you have all those elements located, you simply have to follow the following steps to use the iMac as an external display:

  1. Connect with the Thunderbolt cable, the iMac with the computer.
  2. Turn on both computers.
  3. press the keys Command + F2 at the same time on the keyboard of the iMac that you are going to use as the target screen. At this very moment you will be able to see the content of the other computer on the screen.

You will be able to use that iMac normally as an external monitor, even being able to set it as sound source main of the other computer. You will only have to configure in the sound settings that the iMac is the output source. This is something we are used to in this type of connection. The classic HDMI connection is capable of transferring both image and sound, and this is quite similar to what we have in this case.

In those using mini DisplayPort

If in your case you have a 27-inch iMac with the mini DisplayPort, you will be able to tell if on its back you find a port marked with a square inserted between two stripes. In these cases, it must be said that may also be used with Thunderbolt as we explained before, although if you want to know the steps to follow to use the other port, we will also tell you.

In this case there may be problems regarding sound reproduction on the target iMac. If it is another Mac that you are going to connect, there is a way to be able to check beforehand if you are going to have that problem, since you simply have to go to the system information through the 'About this Mac' section. Then you must look for the 'Audio' section in the 'Hardware' category. Once there you should see if 'HDMI Output' or 'HDMI/DisplayPort Output' appears, thus being able to confirm the possibility of transmitting the audio to the iMac. Obviously, you must have a cable that is compatible for this transfer as another fundamental requirement.

The steps to follow in this case are the following:

  1. Connect with the Mini DisplayPort cable both the iMac and the Mac.
  2. Turn on both computers.
  3. press the keys Command + F2 at the same time on the keyboard of the iMac that we are going to use as the destination screen. At this very moment we can see on the iMac screen the content that we have on our Mac.

As we mentioned in the previous section, in order to activate the sound transmission simply go to the sound settings of the device you are using and select the iMac as the output source for it.

How to disable this functionality

If at any point you want to stop using this functionality and return to using your iMac normally, you can of course remove the cable, but this could cause problems. The most correct thing is that you carry out these steps before:

  1. Turn off both computers, both the iMac used as an external display and the other.
  2. Turn both computers back on.
  3. As you did previously to connect them, hold down the keys Command + F2 on the keyboard.

Once you have done this you will be able to see how this functionality has been reversed and both computers work normally. At that time you can remove the wire that unites both teams and save it. At all times you will also be able to access this function again, resuming the connection.

The 'trick' to do it with newer iMacs

As we previously warned, it is not possible to use these features on the latest Apple computers. However, there is a possibility that while it may be more tedious, can work successfully to make a iMac up to 5K It can even serve as an external display for another Mac or Windows PC. This is mainly due to the fact that in Windows the limitations that are present in this case and that prevent the use of the image sharing options are almost completely eliminated.

But you also have to keep in mind that even if it is configured in Windows, you will not be able to go back to macOS and keep the configuration. When you switch to macOS, the native settings imposed by Apple will be applied and you will not be able to have the iMac as a second screen as you wanted. In this way, if you are a person who is not a fan of Windows, it is obviously not the best thing to consider.

For this you must have installed Windows on a partition of the iMac disk , since it will be through this operating system that you will be able to connect another computer. If you already have it, you will simply need to boot your iMac into it and follow these steps:

  1. Once in Windows, go to 'Settings'.
  2. Choose the 'System' option.
  3. Select the 'Projection on this computer' option. In the options that appear you must have the following boxes activated:
    • only the first time
    • Request to project to this PC

connect imac windows

Once that is done, you must configure the other computer to establish your iMac as the main screen. This you can do via cable The via Wi-Fi , although for the latter you must take into account that both devices are connected to the same network, since it would not be possible otherwise. But it is not limited to the same network, since it also needs to be on the same network frequency. This is vital so that it can be discovered, as if it were any local device.