How to Enable “Target Disk Mode” on a Mac to Transfer Files

If you buy a new MacBook, Apple provides a very simple “Migration Assistant” to transfer your data over Wi-Fi. But what happens if the screen on your old Mac is completely shattered, making it impossible to click the buttons to start the Wi-Fi transfer? Or what if you are a video editor who needs to move 500GB of raw footage to a colleague’s laptop immediately, and you don’t have time to wait for a sluggish network transfer?

macOS includes a brilliant, low-level hardware feature called “Target Disk Mode.” This feature bypasses the operating system entirely and turns the entire Mac computer into nothing more than a giant external hard drive. By connecting two Macs directly with a physical cable, you can achieve lightning-fast data transfers and rescue files from Macs with broken screens or corrupted operating systems.

This guide explains how to initiate Target Disk Mode on both Intel and Apple Silicon Macs.

Requirements

You need two Mac computers and a high-speed data cable to connect them. A standard USB-C charging cable will not work because it is too slow. You must use a true Thunderbolt cable (look for a tiny lightning bolt symbol on the connector tip) or a high-speed USB 3.0 cable.

Method A: Starting an Intel Mac in Target Disk Mode

If the Mac you are trying to pull data from has an Intel processor, the process is incredibly simple.

1. Ensure the target Mac (the one holding the data) is completely turned off.
2. Connect the two Macs using your Thunderbolt cable.
3. Press the power button on the target Mac, and immediately press and hold the “T” key on the keyboard.
4. Keep holding the “T” key until a large Thunderbolt or USB icon appears floating on the screen. The Mac is now in Target Disk Mode.
5. Look at the screen of your other Mac. A new hard drive icon will appear on the desktop, representing the internal drive of the Target Mac. You can now open it and drag files exactly as if it were a standard external USB drive.

Method B: Starting an Apple Silicon (M1/M2/M3) Mac in Target Disk Mode

Apple fundamentally changed the security architecture with their custom Silicon chips. They deprecated the old “T” key method and replaced it with a more secure feature called “Share Disk,” which requires you to boot into the Recovery environment first.

1. Ensure the target Mac (the Apple Silicon machine holding the data) is completely turned off.
2. Connect the two Macs using your Thunderbolt cable.
3. Press and hold the power button on the target Mac. Do not let go.
4. Continue holding the power button even after you see the Apple logo. The screen will say “Continue holding for startup options.”
5. Release the power button when you see a screen that says “Loading startup options.”
6. Click on the icon labeled Options (it looks like a gear) and click Continue.
7. You may be prompted to select a user and enter your administrator password.
8. Once you reach the main Recovery screen, look at the very top menu bar. Click Utilities and select Share Disk.
9. Select the internal Macintosh HD that you want to share, and click Start Sharing.

On your other Mac, the drive will not instantly appear on the desktop. Instead, open the Finder, look in the left-hand sidebar under the “Locations” or “Network” section, and click on the name of the Target Mac. Click Connect As, select “Guest,” and click Connect to access the files.