When a friend, houseguest, or colleague asks to borrow your Mac for a few minutes to check their email or print a boarding pass, handing over your unlocked computer is a massive security risk. Even if you trust them implicitly, they could accidentally delete a crucial file, alter a system setting, or view private messages that pop up on your screen. The safest and most professional way to share your Mac is by enabling the built-in Guest User account.
A Guest User account provides a temporary, heavily restricted workspace. The guest can browse the web and use basic applications, but they cannot access your personal files, change system settings, or install new software. Most importantly, the moment they log out, the Mac automatically deletes all of their browsing history, downloaded files, and temporary data, resetting the account to a pristine state for the next user.
How to Enable the Guest User Account
The Guest User feature is built into macOS, but it is disabled by default. You must be logged into an Administrator account to turn it on.
- Click the Apple Logo in the top-left corner of your screen.
- Select System Settings (or System Preferences on older versions of macOS).
- In the left-hand sidebar, scroll down and click on Users & Groups.
- On the right side of the window, you will see your own account, and below it, an entry labeled Guest User (which will currently say “Off”).
- Click the small Info (i) button next to Guest User.
Your Mac will prompt you to enter your administrator password or use Touch ID to verify you have permission to make changes.
Configuring Guest Permissions
Once you authenticate, a small configuration window will appear.
- Toggle the main switch labeled Allow guests to log in to this computer to the “On” position.
- Parental Controls (Optional): If you are setting up the Guest account for children, you can check the box labeled Limit Adult Websites to activate Apple’s built-in web filter.
- Shared Folders (Optional): By default, guests cannot see anything on your hard drive. However, if you check the box labeled Allow guest users to connect to shared folders, they will be able to access the “Public” folder on your Mac. This is useful if you specifically want to leave a document or photo for them to view.
Click Done. The Guest User account is now active.
How to Use the Guest Account
The next time you wake your Mac from sleep or restart it, the login screen will now display two icons: your personal account and the new Guest User account.
To let someone borrow your computer:
- Click the Apple Logo and select Lock Screen (or Log Out).
- At the login screen, instruct your friend to click the Guest User icon.
- No password is required. The Mac will simply load a fresh, empty desktop.
The Importance of Logging Out
It is vital to understand that the Guest account is completely ephemeral (temporary). If a guest spends an hour downloading photos, writing a document, and saving it to the Guest desktop, all of that data will be permanently destroyed the exact second they log out.
When the guest is finished using your Mac, they must click the Apple Logo and select Log Out Guest User. A warning prompt will appear, explicitly stating that all files will be deleted. Once they confirm, the Mac wipes the temporary workspace clean, ensuring your computer remains uncluttered and the guest’s privacy is protected.