How to keep your websites private on a shared computer

Sharing a computer mostly means sharing a browser, and the browser is logged in to your whole life. There are five ways to keep your part of it to yourself. They differ in how much bother they are every day, which matters more than how strict they are, because the one you stop using protects nothing.

Pick by your situation

• A family computer, and you only want your inbox and chats left alone: lock those few sites (option 5).
• Roommates, or a desk shared at work: give everyone a computer account of their own (option 1).
• Handing your laptop to someone for ten minutes: open a guest window for them (option 3), or lock your browser first.
• A child who uses your computer: a separate account for them, plus a lock on your own sites in case they end up in your browser anyway.

Option 1: A computer account for each person

Windows and macOS can hold several accounts, each with its own password, files and browser. On Windows it's under Settings, Accounts, Other users. On a Mac it's System Settings, Users & Groups.

Nothing else on this page is as private. The person in the other account can't open your browser at all. What you pay is the switching: you sign out or switch user every time someone else needs the machine, and plenty of households drift back to one account because of it.

It also only works if every account has a password and you lock the screen when you get up.

Option 2: Browser profiles

Chrome, Edge and Firefox let each person have a profile, with separate bookmarks, history and logins. Profiles are good for keeping things tidy: your shopping suggestions stop following your partner around.

They aren't private, though. A profile has no password, and switching to someone else's takes two clicks. Treat profiles as separate drawers, not locked ones.

Option 3: A guest window

In Chrome and Edge, click your profile picture and choose the guest option. The guest gets an empty browser with none of your logins, and what they do is wiped when the window closes.

It's meant for a visitor you trust. A guest who closes that window can open your normal profile straight after, so it's a courtesy and not a barrier.

Option 4: Signing out, or using a private window

You can sign out of each site when you're done, or do your personal browsing in an incognito or private window, which forgets your logins when it closes. Both leave nothing behind for the next person.

The price is typing your passwords, and your phone codes, again every time you sit down. It's realistic for a bank you check once a week. It's not for the email and chats you open twenty times a day.

Option 5: A password on the sites, or on the browser

This is what we built Web Lock for. You stay logged in everywhere, and the sites you choose ask for one extra password before they open. It can also lock the browser as a whole when it starts.

1. Add Web Lock to Chrome.
2. Set one password and a recovery email.
3. Tick the sites you want kept private, or turn on Browser Lock to cover everything.

The step-by-step version is in how to password protect any website, and locking the browser itself is in how to lock Chrome.

Where it falls short: it's an extension, so it works in the one browser profile where it's installed, and a person who knows their way around the browser's settings can take it out. It suits the people you live or work with. It isn't built to stop someone who's set on getting in and knows computers.

What we'd actually do

• At home with family: option 5 by itself. It's the only one people keep using.
• With roommates or at work: option 1, and option 5 on top if you sometimes leave your account open.
• For a visitor: option 3, every time. It takes a few seconds.

Three things people forget

• Saved passwords. Your browser will show them to anyone unless your computer account has a password for it to ask for. Set one even if you never lock the screen.
• The Downloads folder. No browser setting hides files you've downloaded. Bank statements and payslips tend to pile up there, so move or delete them.
• The phone that mirrors everything. If your messages also show up on a shared tablet or a family computer through a phone link, a browser lock won't cover that.

Questions people ask

Do Chrome profiles have passwords?

No. A profile keeps bookmarks, history and logins apart, but anyone can click its picture and open it. Edge and Firefox profiles work the same way.

Is a guest window the same as incognito?

No. A guest window starts empty, with none of your bookmarks, history or logins. An incognito window is still your own browser, it only forgets what you did in it once you close it.

What's the quickest way to lock my computer when I step away?

On Windows, press the Windows key and L together. On a Mac, press Control, Command and Q together. Both go to the login screen without closing anything.

Can someone see my saved passwords if they use my browser?

Chrome, Edge and Firefox can ask for your computer's password before they show a saved password, but only if your computer account has one. Without it, the saved passwords are a few clicks away.

Is a site lock enough on a work computer?

It keeps coworkers at your desk out of your personal inbox. It doesn't hide anything from the company itself: whoever manages a work computer can still see how it's used.