Connect accessories to your iMac
You can connect your iMac with other devices, like a keyboard, mouse, or trackpad; wearable devices like AirPods; and more. There are two ways to connect accessories: wirelessly using Bluetooth technology or by connecting a cable from the accessory to one of the Thunderbolt / USB 4 ports or USB 3 ports (if you have the four-port model iMac) on your iMac.
Before you begin. Before you connect an accessory to your iMac, do the following:
Consult the documentation that came with your accessory.
If you are connecting with a cable, make sure you have the correct cable. You may also need an adapter to connect the cable to one of the Thunderbolt / USB 4 or USB 3 ports (if you have the four-port model iMac) on your iMac. To learn more about your ports and their capabilities, see Take a tour: iMac.
Make sure your iMac is updated to the latest version of macOS.
Connect a wireless accessory
Turn Bluetooth on. Click 
Pair a Bluetooth accessory. The first time you use a Bluetooth accessory with your iMac, you must pair them. Consult the documentation that came with your accessory to make sure it is ready to pair—for instance, you may need to flip a switch on the accessory to turn on Bluetooth. Both your Mac and the accessory must be turned on and near each other.
When your accessory is ready to pair, open System Settings on your Mac and click Bluetooth in the sidebar. Select the accessory in the Nearby Devices list, then click Connect.
Connect a Bluetooth accessory. Your accessory automatically connects to your iMac after you’ve paired it. To see what Bluetooth devices you have connected to your iMac, click 
If your accessory isn’t automatically connecting, open System Settings on your Mac and click Bluetooth. Make sure the accessory appears in the My Devices list. If it doesn’t appear, follow the steps to pair the accessory.
Disconnect or forget a Bluetooth accessory. To disconnect a Bluetooth accessory, open System Settings on your Mac and click Bluetooth. In the My Devices list, move your pointer over the accessory, then click Disconnect when it appears. To forget a Bluetooth accessory so your iMac doesn’t automatically connect to it, click 
Connect a Magic Keyboard, Magic Mouse, or Magic Trackpad. If your iMac came with a Magic Keyboard, Magic Mouse, or Magic Trackpad, they are already paired with your Mac. If you purchased a Magic Keyboard, Magic Mouse, or Magic Trackpad separately or need to pair it again, connect the accessory to your iMac using the cable provided with the accessory. Then, slide the switch on your accessory to on, so that green is visible. Your accessory then pairs with your Mac.
After the accessory is paired with your iMac, you can disconnect the cable and use the accessory wirelessly. Your Magic Mouse, Magic Trackpad, or Magic Keyboard automatically connects to your Mac when Bluetooth is turned on.
For information about input devices, see Magic Keyboard, Magic Mouse, and Magic Trackpad.
Note: Magic Keyboard, Magic Trackpad, and Magic Mouse behave like a wired keyboard or pointing device when connected using their included cable. Bluetooth isn’t used, and all communication is over the cable.
Connect AirPods with your iMac. To pair and connect AirPods, see Pair AirPods with an Apple Device.
Connect an accessory with a cable
Some accessories can be connected to your iMac with a cable. Depending on the capabilities of the accessory and the cable, you may also be able to charge the accessory or transfer data when connected.
Consult the documentation that came with your accessory before connecting it. Some accessories have an additional power source that also needs to be plugged in.
To connect an accessory, you need to use a cable that fits both the port on your accessory as well the Thunderbolt / USB 4 port, or the USB 3 port (if you have the four-port model iMac), on your iMac. If the cable doesn’t have the right connector for your Mac, you may use an adapter to connect the cable. For more information about adapters, what they look like, and what ports to use, see Adapters for the Thunderbolt 4, Thunderbolt 3, or USB-C port on your Mac.
Tip: Some accessories need to be approved the first time they’re connected. See Allow accessories to connect to Mac to learn more.
Learn more. See Bluetooth settings on Mac and About USB on Mac. To learn more about connecting a Magic Mouse, Magic Trackpad, or Magic Keyboard, see Set up your Magic Keyboard, Magic Mouse, or Magic Trackpad with your Mac. If you see a note that USB devices are disabled, see If you see USB Devices Disabled on your Mac.