Use Find My Mac
If you misplace your Mac, Find My Mac helps you locate and protect it. Before your Mac goes missing, make sure you set up Find My Mac and know how to locate and protect your Mac using the Find My iPhone on iCloud.com or an iOS device.
As long as your lost Mac isn’t in sleep and is connected to a Wi-Fi network or tethered to a personal hotspot, you can locate it on a map. If it’s connected to the Internet via Ethernet, Wi-Fi, or a personal hotspot, you can play a sound on it, lock it, or erase it completely.
Set up Find My Mac
Choose Apple menu > System Preferences, then click iCloud.
If you’re asked to sign in, enter your Apple ID or, if you don’t have one, click Create new Apple ID, then follow the instructions.
Select Find My Mac. If asked to allow Find My Mac to use the location of your Mac, click Allow.
If a Details button appears next to Find My Mac, click the button, click Open Security & Privacy, then click Enable Location Services.
The Details button appears if Location Services is turned off in Security & Privacy preferences.
If Enable Location Services is dimmed in Security & Privacy preferences, click the lock icon , then type the name and password of an administrator for the computer.
For added security, make sure all user accounts have secure passwords and that automatic login is turned off in Users & Groups preferences. For instructions, see Change the login password and If you don’t see a login window when you start the Mac. To open Users & Groups preferences, choose Apple menu > System Preferences, then click Users & Groups.
Locate and protect your missing Mac
When you need to locate and protect your missing Mac, do either of the following:
For more information, see Find My iPhone overview in iCloud Help.
On an iOS device: Use the Find My iPhone app.
For more information, tap Help in the Find My iPhone app.
With the Find My iPhone app on iCloud.com or an iOS device, you can do the following:
Locate your Mac on a map: See the approximate location of your Mac when it’s connected to a Wi-Fi network.
Play a sound on your Mac: If you think your lost Mac is nearby, you can play a sound on it to help you find it.
Lock your Mac: If you can’t locate your Mac, you can lock it with a code so that others can’t use it.
Erase your Mac: Remotely erase the entire contents of your Mac, and lock it with a code so that others can’t use it.
Before erasing your Mac, try to locate it on a map and play a sound on it. After erasing it, you can’t use Find My iPhone to do either. However, you can see the location where it last connected to a Wi-Fi network.
If your Mac is shut down or offline when you try to do any of the above, the action takes place the next time your Mac is online.
Note: Any credit or debit cards set up for Apple Pay on your Mac are suspended for your Mac if you lock it, or removed from your Mac if you erase it, even if your Mac is offline. Apple Pay is also disabled for your Mac in either case. You can resume using suspended cards on your Mac after you unlock it and sign in to iCloud again.