All modern smartphone, tablet, and desktop operating systems offer secure ways to give a guest access to your computer. Lock them to a specific app or give them restricted access to your PC. Forget looking over their shoulder!

Just using a profile switcher like the one in Chrome isn’t the best way to do this, although it does at least give your guest their own browsing session — assuming they don’t switch back to yours with a few clicks.

iPhone and iPad

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The “Guided Access” feature on iOS allows you to temporarily restrict your iPhone or iPad to a single app. You can then hand it over to someone else and allow them to use it — for example, to allow a friend to place a phone call without letting them see other apps, or to allow a child to play a game without worrying about them tapping through your emails. You’ll need to enter a passcode (or use Touch ID) to leave Guided Access.

To enable Guided Access, head to the Settings app, tap General, and tap Accessibility. Scroll down and tap “Guided Access” under Learning.

To activate Guided Access, open an app and then press the Home button three times in a row. You’ll be able to enable Guided Access and set a passcode. To leave the app, you’ll need to press the Home button three times and enter the passcode. Hand your phone or tablet to someone and they’ll be locked to that specific app.

Android

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Android 5.0 Lollipop offers a “screen pinning” feature that allows you to lock your phone or tablet to single app before handing it to someone else — just like Guided Access on iOS. To enable this feature, open the Settings app, tap the Security category, and tap Screen pinning under Advanced. Enable the Screen pinning option.

Next, navigate to the app you want to “pin.” Open the Activity overview — tap the square button at the bottom of the screen — and tap the Pin icon on the thumbnail. (If you don’t see it, scroll down.) To unpin the app, touch and hold the activity overview button — the square one. You’ll have to enter your device’s PIN code to exit the app if you chose this option, so guests will be locked to that specific app until you get your phone or tablet back.

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Android 5.0 Lollipop also offers a Guest user mode. As of Android 5, user accounts are available on both smartphones and tablets. To use it, open the notification drawer, tap the user icon, and select Guest. This gives the guest restricted access to your smartphone or tablet, without access to your personal data. The data in Guest user mode is stored only temporarily, so you’ll be able to choose whether you want to resume the previous guest session or start fresh every time you sign in.

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This isn’t so easy on previous versions of Android — that is, Android 4.4 and lower. If you have an Android tablet running Android 4.2, 4.3, or 4.4, you can at least create your own Guest user account. Android phones are out of luck, unless the device’s manufacturer built some custom guest-mode software into them — and some have.

Windows

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Microsoft Windows has a Guest account, but it isn’t enabled by default. To use it, you’ll need to visit the Control Panel and enable the Guest account. After this, you can log out of your computer — or just select Switch User — and log in with the Guest account. The Guest account doesn’t need a password. Any changes you make to the computer while in guest mode will be wiped clean after you log out, so every guest user has a fresh slate. These accounts are restricted, so they can’t install software or dig through your personal files.

To enable it, open the Control Panel and navigate to User Accounts and Family Safety > User Accounts > Manage Another Account. Click the Guest account and enable it.

Mac OS X

Mac OS X also has a Guest account, and it works similarly — it gives a person restricted access to the computer so they can’t make changes or access your personal files. When they log out, any changes they’ve made or files they’ve downloaded to the Guest account will be wiped away.

This feature is enabled by default, so you can just log out by clicking the Apple menu and selecting Log Out, and then log in with the Guest User account. To change these options, open the System Preferences window and select Users & Groups. You can choose whether the Guest account is enabled from here. You can also enable the “Fast User Switching” menu from here, which allows you to quickly switch between user accounts so you can quickly give a guest access to the guest account without logging out of your Mac first.

Linux

Linux desktops often have guest accounts that work in the same way. Select the Guest user to get a restricted session, and any changes made to that session will be wiped away after you log out. Look for the Guest user option on your Linux desktop’s login screen. If you can’t find it, check your Linux desktop’s Users or Login preferences window and look for an option to enable a Guest user.

For example, on Ubuntu’s Unity desktop, just click the Guest Session icon below the list of users on the computer.

Chrome OS

Chromebooks offer a guest user account, too. This works just like a typical Chrome OS user account, but it allows you to browse the web without logging in with a Google account first. Any files downloaded or settings changed in the Guest account will be wiped away after you log out. It’s a convenient way to have someone borrow your Chromebook without having them enter their password and having their stuff synced to your device.

To use this feature, just log out of your Chromebook and click the Browse as Guest option at the bottom of the login screen.

Sure, you don’t have to use these modes if you trust the guest. But, when you need to hand a smartphone, tablet, or phone to a kid, it’s the safest way. Even if you trust someone, you don’t have to worry about them looking at your personal stuff or messing with anything — even accidentally.