Using Your Imac As A Monitor: A Simple Guide

If you're looking to use your iMac as a monitor, you're in luck! There are several ways to do this, including using Target Display Mode, Luna Display, Duet Display, or a video capture card. Target Display Mode is available on iMacs made between 2009 and 2014, allowing them to be used as displays for other Macs. Newer iMacs, however, do not support this mode. Luna Display and Duet Display are two popular options that provide similar functionality, but they require additional hardware or a subscription cost. Alternatively, you can use a video capture card and HDMI-to-USB converter to connect your Nintendo Switch to your iMac.

Target Display Mode for iMacs made between 2009 and 2014

Target Display Mode is a feature available with certain older Mac models. iMacs made between late 2009 and 2013 can be used as a monitor for other Macs. The 27-inch iMacs introduced in late 2009 included the first version of Target Display Mode, a feature that allowed iMacs to be used as displays for other Apple devices.

To use Target Display Mode, you need to ensure that your iMac is running macOS High Sierra (10.13.6) or earlier, and the source Mac must have macOS Catalina (10.15) or earlier installed. The iMac used as a display must be connected to the source Mac using either a Mini DisplayPort cable or a Thunderbolt cable, depending on the model.

Once the two Macs are connected, press Command+F2 on the iMac to enter Target Display Mode. You should now see the screen contents of the source Mac. To exit Target Display Mode, simply press Command+F2 again, or disconnect the iMac from the source Mac.

It is important to note that while in Target Display Mode, the iMac continues to run its operating system and any open applications. Additionally, the source Mac cannot access the iMac's built-in camera or ports. Target Display Mode is no longer supported on newer iMac models due to hardware and software limitations.

Luna Display or Duet Display

Luna Display and Duet Display are apps that allow you to use your iMac as a second monitor for your primary computer. Both apps support Mac and PC, and you can use any of these devices interchangeably as a second display.

Luna Display

Luna Display supports full 5K iMac resolutions and can connect over USB, Wi-Fi, Ethernet, or Thunderbolt. To set up Luna Display, follow these steps:

• Plug in your Luna Display dongle into the USB-C port that supports Thunderbolt or DisplayPort on your primary Mac or PC.
• Connect your iMac to your computer using a cable. While Luna Display supports Wi-Fi connections, it is recommended to use a cable connection for better performance and reliability.
• Download and launch the Luna Display apps on both your primary computer and iMac.
• Follow the on-screen instructions to configure your iMac as a monitor.

Duet Display

Duet Display offers zero-lag performance and allows you to mirror your display or use it as a graphics tablet. To set up Duet Display, follow these steps:

• Download and install Duet on both your primary computer and iMac from the official website (https://www.duetdisplay.com).
• Log into Duet with the same account on both devices and sign up for Duet Air or Duet Pro.
• Click the "Desktop" tab in Duet on your iMac and select "Mirror" or "Extend".
• Move your cursor to the edge of your primary display, and it will automatically appear on the iMac. You can then drag windows and applications between the two screens.

Both Luna Display and Duet Display provide effective solutions for using your iMac as a second monitor, offering increased productivity and enhanced desktop workspace.

Sidecar for iPad to Mac

You can use your iPad as a second display for your Mac with a feature called Sidecar. This feature is available on macOS Catalina or later and an iPad running iOS 13 or later.

To use Sidecar, both devices must be signed in with the same Apple Account and be within 30 feet (10 meters) of each other. They should also have Wi-Fi, Bluetooth, and Handoff turned on. You can use Sidecar wirelessly or with a USB cable.

Here's how to set it up:

• Connect your iPad to your Mac with a USB cable or ensure that both devices are connected to the same Wi-Fi network.
• On your Mac, go to the Apple menu and select System Settings.
• Click on Displays in the sidebar.
• Choose your iPad from the list of available displays.
• Adjust any Sidecar options as needed, such as showing a sidebar or Touch Bar on your iPad or extending or mirroring your Mac display.
• You can also adjust the arrangement of your Mac and iPad displays by clicking Arrange and then dragging the displays into your desired position.

Once you've set up Sidecar, you can move windows between your Mac and iPad by dragging them to the edge of the screen or by choosing Window > "Move to" in the app you're using. You can also use the sidebar on your iPad to access commonly used Mac controls, such as Command, Shift, and other modifier keys.

If you want to stop using Sidecar, you can do so by clicking on the Display option in the menu bar on your Mac and deselecting your iPad from the list below "Mirror or extend to." On your iPad, you can tap the "X" at the bottom of the sidebar to end the Sidecar session.

Please note that while Sidecar allows you to use your iPad as a second display, it is not designed to work with touch gestures. You will primarily control your iPad using the trackpad or mouse of your Mac or the Apple Pencil.

Pair iMac with an external monitor

Pairing an iMac with an external monitor is a simple process. Firstly, ensure that your iMac is compatible with an external monitor. This feature is available with certain older Mac models, specifically iMac models introduced between 2009 and mid-2014.

Once you've confirmed compatibility, follow these steps:

• Ensure that your iMac is turned on and meets the system requirements.
• Connect your chosen external monitor to your iMac using the appropriate cable. For iMacs introduced between 2009 and 2010, use a Mini DisplayPort cable. For iMacs introduced between 2011 and mid-2014, use a Thunderbolt or Thunderbolt 2 cable.
• After establishing the connection, press Command-F2 on your iMac's keyboard. You should now see the external monitor displaying the iMac's desktop.
• To exit this display mode, simply press Command-F2 again, disconnect the cable, or restart your iMac.

It's important to note that while in this display mode, your iMac will continue to run its operating system and any open applications. Additionally, the external monitor cannot access the iMac's built-in camera or ports. Any external devices should be connected directly to the iMac.

Connect two Macs with a Mini DisplayPort or Thunderbolt cable

Connecting two Macs with a Mini DisplayPort or Thunderbolt cable is a straightforward process. Here's a detailed guide on how to do it:

Step 1: Check Compatibility

First, ensure that your iMac models are compatible with the target display mode. The following iMac models can be used as an external display when connected to another Mac:

• IMac models introduced in 2011, 2012, 2013, and mid-2014.
• 24-inch and 27-inch iMac models introduced in 2009 and 2010.

Additionally, the iMac used as the display must have macOS High Sierra or earlier installed, and the other Mac must be a 2019 model or earlier with macOS Catalina or earlier.

Step 2: Prepare the Macs

Make sure both iMacs are turned on and meet the system requirements mentioned above. The Mac you are connecting to should be logged into a macOS user account.

Step 3: Connect with Cable

Use a Mini DisplayPort or Thunderbolt cable to connect the two iMacs. If you are using multiple iMacs as displays, ensure that each iMac is connected directly to a Thunderbolt port on the other Mac, not another iMac.

Step 4: Activate Target Display Mode

Once the iMacs are connected, press Command-F2 on the keyboard of the iMac you are using as the display. You should now see the desktop of the other Mac. To exit target display mode, simply press Command-F2 again or disconnect the cable.

Troubleshooting:

If your iMac doesn't show the desktop of the other Mac, try these steps:

• Restart the other Mac.
• Unplug the Thunderbolt or Mini DisplayPort cable from the other Mac, then plug it back in.
• Press Command-F2 on the iMac again.
• If you are logged into the iMac you want to use as a display, log out by going to the Apple menu and choosing Log Out. Then, press Command-F2 again.
• Go to System Preferences and click on Keyboard. If "Use F1, F2, etc. keys as standard function keys" is selected, target display mode will use Command-Fn-F2 instead of Command-F2.
• Ensure your iMac is using macOS High Sierra 10.13.6 or earlier, as later versions do not support target display mode.

Frequently asked questions