How To Lock Your Mac

With the increasing amount of personal information that we store on our Macs, taking steps to keep it away from prying eyes and sticky fingers is becoming more important day by day. Sure, the contents of your Mac may not exactly warrant CIA-type security, but knowing how to lock your Mac while you’re not using it can save you from a thousand dollars or two of replacement costs or from the embarrassment of having a ridiculous Facebook status gleefully posted by your friend on your behalf while you were snoring your hangover away.

How to Lock Your Mac

There are several ways to lock your Mac to prevent unauthorized use. Some of these are part of your Mac’s built-in features, but one of them you have to get from a third party.

Startup Login

The startup login is your Mac’s first line of defense against unauthorized use. When startup login is enabled on your Mac, you (or whoever is using your laptop) will be required to type in the password that was set for it before you can access its contents.

To lock your Mac by enabling startup login,

  1. Go to the Apple Menu.
  2. Select “System Preferences.”
  3. Click on “Accounts.”
  4. Choose “Login Options.”
  5. Tick the box that says “Disable Automatic Login”


Idle Lock

Idle lock happens when your Mac did not detect any type of activity after a certain amount of time — prompting it to lock up automatically. You will then be required to enter your login password before you can unlock it and use it again, which is pretty useful for users who need to go for quick breaks every now and then but don’t want anyone touching their Macs while they’re gone.

To lock your Mac using the idle lock,

  1. Go to the Apple Menu.
  2. Select “System Preferences.”
  3. Select “Security and Privacy.”
  4. Tick the box that says “Require Password.”
  5. Choose the amount of time you want to pass after the last detected activity before your Mac locks up.
  6. Tick the box that says “Disable Automatic Login.”
  7. Tick the box that says “Show a Message When the Screen is Locked” and leave a custom message for anyone who will attempt to open your Mac (optional).


If you need to go away real quick and you don’t want to wait for the idle lock to kick in on its own, you can easily lock your Mac by pressing CTRL + Shift + Power/Eject on the older models or from activating it through the Touch Bar on the newer ones.

Administrator Lock

Using an Administrator account is a way to lock your Mac by preventing guest or standard users from accessing settings or permissions that you wouldn’t want them to be able to change.

An Administrator lock is enabled by default when trying to access sensitive file locations such as your Mac’s Library folder (which contains files that could cause your Mac to stop working when deleted or wrongly changed in some way) or executing potentially dangerous commands such as installing applications, but you can also manually enable it for other less-sensitive folders or even entire disks as well.

To do this,

  1. Go to the location of the disk or the individual folder that you want to limit access to.
  2. Select the disk or file.
  3. Click on “File.”
  4. Choose “Get Info.”
  5. Click on “Sharing and Permissions.”
  6. Choose what kind of privileges you want non-administrators to have.
    1. Choose “Read Only” if you want non-administrators to be able to read the contents of the disk or the folder but not be able to change it.
    2. Choose “Write Only” if you want non-administrators to be able to drop files into that disk or folder, but not be able to open or change existing content.
    3. Choose “No Access” if you want non-administrators to have no access whatsoever to the contents of that disk or folder.


Firmware Lock 

The firmware lock is a lock designed for Mac users who want an additional layer of protection in case an experienced intruder was able to bypass the startup login. It works by preventing unauthorized users from accessing your Mac by only allowing it to boot from the disk that was originally used to set it up.

To lock your Mac using the firmware protection,

  1. Open macOS Recovery by holding down the Command and R keys immediately after turning on your Mac.
  2. Wait until you see the Apple logo.
  3. Wait for the “Utilities” window to appear.
  4. Click on “Utilities.”
  5. Select “Firmware Password Utility” (Note: This feature is only available on certain Mac models).
  6. Click on “Turn On Firmware Password.”
  7. Type in your desired firmware password.
  8. Click on “Set Password.”
  9. Select “Quit Firmware Password Utility.”
  10. Restart your Mac.


After your Mac has been restarted, the firmware lock will run quietly in the background and won’t be activated until you or someone else attempts to start it by using a different disk or by opening macOS Recovery.

Please note that the firmware password is purposely designed to make it very difficult for ordinary users to reset, so make sure that you don’t forget the firmware password so that you don’t get locked out of your own Mac. If it did happen, you need to bring your Mac to an Apple Store or an authorized service center to have it reset.


Physical Lock

If you’ve taken a liking to all these basic protective features and you want to go the extra mile to make sure that no one else touches your Mac, you can also use a physical device to make sure it secure.

Yes, using a physical device to lock your Mac may sound like a joke, but the product very much exists. There are several companies that manufacture laptop locks that usually come in the form of metal clamps and steel cables that you can attach to your Mac on one end and to a sturdy furniture or post on the other.

There even used to be a built-in slot for them on older Mac models (that slot has since been removed in the newer and thinner Retina models, but there are additional accessories that can be bought to get around this issue) to make it easy for you to lock your Mac in place if you ever needed to leave it for any reason for a couple of minutes.

Of course, no matter how you lock your Mac, no amount of protection can save it from a determined snoop or a well-experienced thief, but at the very least, they can help your Mac put up a good fight like what this CCTV video demonstrates.


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