Target disk mode can be useful when you need to move files quickly between computers, or get files from a Mac that doesn't have a working display. It requires two Mac computers that are connected by cable using any of these ports:
- Thunderbolt 3 (USB-C)
Available on iMac Pro and iMac models from 2017, and MacBook Pro models from 2016 or later.
Available on MacBook models from 2015 or later.
- Thunderbolt 2
Target disk mode doesn't support connections that use an Apple USB-C Charge Cable, USB-A to USB-A cable, or Mini DisplayPort cable.
Connect your computers with the correct cable
If you're connecting with Thunderbolt 3 (USB-C) or USB-C:
- To connect a Thunderbolt 3 (USB-C) port to another Thunderbolt 3 (USB-C) port or a USB-C port, use the Apple Thunderbolt 3 (USB-C) Cable.
- To connect a USB-C port to another USB-C port or a Thunderbolt 3 (USB-C) port, use the Apple Thunderbolt 3 (USB-C) Cable.
- To connect a Thunderbolt 3 (USB-C) port to a Thunderbolt 2 port, use the Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter combined with a Thunderbolt 2 cable.
- To connect a USB-C port to a USB-A port, use a USB-A to USB-C cable that supports USB 3.0 or USB 3.1, such as the Belkin USB-A to USB-C Cable (USB 3.1).
Start up in target disk mode
After connecting your computers with the correct cable, follow these steps:
- If the Mac that you want to use as a disk is turned on, choose Apple () menu > System Preferences, then click Startup Disk. Click Target Disk Mode, then click Restart when you're asked to confirm.
- If the Mac that you want to use as a disk is turned off or doesn't have a working display, turn it on and then immediately press and hold the T key while it starts up.
- The Mac starts up in target disk mode, then appears as a disk on the desktop of your other Mac. You can now use it as you would any other hard disk.
To exit target disk mode, press and hold the power button on the Mac you're using as a disk. Then disconnect the cable.
As an alternative to target disk mode, you can use AirDrop to send content between two Mac computers wirelessly.