How to lock Facebook and Messenger with a password

Facebook keeps you logged in until you log out. On a computer other people use, that means your feed, your private messages and the Post button are open to whoever sits down next. Facebook doesn't offer a lock for its website, so this is how to add your own.

What Facebook's own settings do

• Logging out works if you do it every single time. Watch for the "save your login info" offer when you leave: say yes and your profile picture stays on the login page, where one click logs you back in with no password.
• Two-factor authentication and login alerts stop a stranger from getting into your account on their device. They don't help with a browser that's logged in already.
• Where you're logged in, in Facebook's security settings, lists every device using your account and lets you log any of them out from afar. Handy when you forgot to log out at a friend's place.

All three are worth having. None of them asks for a password when Facebook is opened on your own computer.

Lock Facebook with Web Lock

1. Add Web Lock to Chrome. The setup page opens when it finishes installing.
2. Make up a password, and enter an email address where a reset code can reach you.
3. Setup then shows a short list of sites. facebook.com is on it, so tick it.
4. Go to Facebook in a new tab and check that the lock screen is there.

If you set up Web Lock some time ago, open it from its icon by the address bar, go to Locked sites and tick or type facebook.com.

What about Messenger?

Your chats can be reached in three places, and it helps to know which the lock covers:

• The Messages page on Facebook is part of facebook.com, so it's locked.
• The chat pop-ups in the corner of every Facebook page are locked too, since no Facebook page loads.
• messenger.com is a different address. If you open your chats there, add messenger.com to your locked sites as well. It's in the same list of suggestions.

You might think of locking only the Messages page and leaving the feed open for the family. We'd skip that. Because of the pop-ups, a chat is one click away from any page on Facebook.

Message previews can still appear

If you once clicked Allow when Facebook asked to send notifications, a new message can show its sender and first line in the corner of the screen, locked or not. The browser shows those, not the Facebook page.

To stop them, open your browser's settings, search for notifications, find facebook.com in the list of sites and change it to blocked. Do the same for messenger.com if it's there.

Instagram and the rest

Instagram on a computer behaves the same as Facebook: it stays logged in and has no lock. Add instagram.com if you use it there. The same goes for any other social site. One password opens all of them, so adding more sites doesn't mean more to remember.

Two habits worth keeping

• Shut the Facebook tab when you get up. Web Lock asks for the password at the moment Facebook is opened. A tab you've unlocked and left on screen is still readable.
• Think before ticking "Keep open until I close the browser". It saves typing when you're alone. On a shared computer it means the next person gets in without the password until the browser is quit.

Sharing more than Facebook? Keeping your websites private on a shared computer compares the other options, including separate accounts.

Questions people ask

Does Facebook have a password lock for its website?

No. Once you're logged in on a browser, Facebook opens straight to your feed. Its security settings deal with people logging in from somewhere else, not with someone sitting at your computer.

Will I be logged out of Facebook when it's locked?

No. You stay logged in. The lock screen comes first, and your feed loads normally after you type the Web Lock password.

Can I lock Messenger and leave the rest of Facebook open?

Not reliably. Facebook shows your chats in pop-up windows on its other pages too, so locking only the messages page leaves them reachable. Lock facebook.com as a whole.

Does this lock the Facebook app on my phone?

No. Web Lock works in a computer's browser. On a phone, use the app lock in the phone's own settings. Recent iPhones can ask for Face ID before an app opens: hold the app's icon and choose Require Face ID.