How to Transfer Files Between Two Macs Using Target Disk Mode

AirDrop is undeniably magical for sending a few photos or a PDF between Apple devices. However, if you have just purchased a new Mac and need to transfer 500GB of video files or a massive Logic Pro project, AirDrop will likely drop the connection halfway through, leaving you incredibly frustrated.

For enormous file transfers, wireless protocols are simply too slow and unreliable. The fastest, most professional way to move massive amounts of data is to learn how to transfer files between two Macs using Target Disk Mode (or Mac Sharing Mode on newer models) via a physical cable.

What is Target Disk Mode?

Target Disk Mode is a low-level hardware feature built into the Mac firmware. It completely bypasses the macOS operating system and forces the computer to behave exactly like an external hard drive. When you connect it to a second Mac, it mounts on the desktop, allowing you to drag and drop files at blistering read/write speeds.

The Most Common Mistake: Using the Wrong Cable

Before you begin, you must ensure you have the correct cable. The white USB-C charging cable that comes in the box with a MacBook will not work. While it has USB-C connectors on both ends, it is designed strictly for delivering power and transfers data at abysmally slow USB 2.0 speeds.

To use Target Disk Mode effectively, you must use a dedicated Thunderbolt 3 or Thunderbolt 4 cable. You can identify these cables by the small lightning bolt icon etched into the metal or plastic connector housing.

How to Use Target Disk Mode on Intel Macs

If the Mac you want to pull files from (the target) has an Intel processor, follow these steps:

1. Connect the two Macs using your Thunderbolt cable.
2. Ensure the target Mac is completely shut down.
3. Turn on the target Mac and immediately press and hold the T key on the keyboard.
4. Keep holding the key until you see a Thunderbolt or USB icon floating on a dark screen.
5. Move to your other Mac (the host). The target Mac’s internal hard drive will appear on the desktop or in the Finder sidebar, usually named “Macintosh HD”.
6. Open it and drag your files across just like a normal external drive.

How to Use Mac Sharing Mode on Apple Silicon (M-Series) Macs

When Apple transitioned to their own M-series chips (M1, M2, M3), they removed the traditional Target Disk Mode and replaced it with a more secure feature called Mac Sharing Mode.

1. Connect the two Macs using your Thunderbolt cable.
2. Ensure the target Apple Silicon Mac is completely shut down.
3. Press and hold the Power button (or Touch ID button). Do not let go when the Apple logo appears.
4. Keep holding it until the screen says “Loading startup options…”
5. Click on Options (the gear icon) and click Continue.
6. If prompted, select a user account and enter your administrator password.
7. At the very top of the screen, click the Utilities menu in the menu bar, then select Share Disk.
8. Select the internal drive you want to share and click Start Sharing.
9. Move to your other Mac (the host). Open Finder and click on Network in the sidebar.
10. Double-click the target Mac, click Connect As, select Guest, and click Connect.

The drive will now mount, allowing you to transfer your files at peak Thunderbolt speeds.

Ejecting Safely

When your transfer is complete, you must safely eject the drive to prevent data corruption. On the host Mac, right-click the mounted drive icon and select Eject. Only then should you disconnect the Thunderbolt cable and restart the target Mac normally.