To lock WhatsApp, go to Settings, then Privacy, then App lock. On Android switch on the biometric option, and on iPhone turn on Require Face ID or Touch ID. You can still answer calls while it's locked, and your phone's PIN or passcode works as a backup.
Your phone's screen lock keeps strangers out, but it doesn't help when you hand your unlocked phone to a friend to show them a photo. WhatsApp's app lock adds a second door: even on an unlocked phone, WhatsApp asks for your face or fingerprint before it opens. There's also a separate chat lock if you only want to hide a few conversations. Here's how both work.
How to lock WhatsApp on Android
- Open WhatsApp and tap the three dots, then Settings.
- Tap Privacy, then App lock.
- Switch on the biometric toggle at the top of the screen.
- Confirm with your fingerprint or face.
- Choose how long WhatsApp waits before asking again, and whether message text shows in notifications.
You need a fingerprint or face scanner set up in your phone's settings first. WhatsApp says app lock needs Android 6.0 or later with a fingerprint sensor that supports Google's fingerprint system, and face unlocking only works on phones with a face scanner. A few older models, including the Samsung Galaxy S5, Galaxy Note 4 and Galaxy Note 8, aren't supported.
How to lock WhatsApp on iPhone
- Open WhatsApp and tap Settings.
- Tap Privacy, then App Lock.
- Turn on Require Face ID (or Touch ID on older iPhones).
- Pick when it locks: Immediately, After 1 minute, After 15 minutes or After 1 hour.
Face ID or Touch ID has to be set up in your iPhone's own settings before WhatsApp can use it.
How to lock WhatsApp Web and Desktop
On a computer there's no fingerprint, so WhatsApp Web uses a password instead. Go to Settings, then Privacy, then App lock, and set a password of 6 to 128 characters. You can have it lock after 1 minute, 15 minutes, 1 hour or 8 hours. While it's locked, notifications don't appear. To lock it instantly when you step away, use the keyboard shortcut: Cmd Ctrl L on a Mac or Ctrl Alt L on Windows.
| Device | Opens with | Auto-lock options |
|---|---|---|
| Android | Fingerprint or face, phone PIN as backup | Your choice of delay |
| iPhone | Face ID or Touch ID, passcode as backup | Immediately, 1 minute, 15 minutes or 1 hour |
| WhatsApp Web | A password of 6 to 128 characters | 1 minute, 15 minutes, 1 hour or 8 hours |
What still works when WhatsApp is locked
- Calls. You can still answer WhatsApp calls on both Android and iPhone.
- Replies from notifications on iPhone. WhatsApp says you can still reply to messages from notifications when it's locked.
- Notification previews on Android, but only if you turned on Show content in notifications.
That last point is the gap people miss. If you lock WhatsApp but leave message previews showing on your lock screen, anyone glancing at your phone can still read the first line of a message. For full privacy, hide previews too.
App lock vs chat lock: which do you need?
WhatsApp has two different locks, and they solve different problems.
| App lock | Chat lock | |
|---|---|---|
| What it locks | The whole app | Chosen chats only |
| Where locked chats go | Nowhere, the app just asks for your face or fingerprint | A hidden folder behind extra authentication |
| Notifications | Previews optional on Android | Show WhatsApp instead of the contact name |
| Does the other person know? | Not notified | WhatsApp says they aren't notified |
Chat lock is useful if you're happy for people to use WhatsApp on your phone but want a few conversations, such as a medical group or a surprise party chat, kept away from view. Locked chats sit in their own folder, and WhatsApp says the other people in the chat aren't notified. Calls from those contacts still come through.
Lock not working?
- Set up fingerprint, face recognition, Face ID or Touch ID in your phone's settings first.
- Update WhatsApp to the latest version.
- Check your phone model is supported. Some older Samsung phones aren't.
- If the scan fails, use your phone PIN or passcode. WhatsApp allows that as a backup.
If you're worried about who else can see your activity, read whether WhatsApp tells people when you screenshot. And if your account itself has been limited, my guide on why WhatsApp is restricted explains what's going on.
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Who should turn it on
I'd switch app lock on if you share a tablet with your family, hand your phone to children to play games, or run your business through WhatsApp on the same phone you lend to friends. It's also worth it if you leave your phone on your desk at work. The few seconds it adds each time you open WhatsApp are a fair trade for knowing nobody can scroll your chats while your back is turned.
Is your fingerprint shared with WhatsApp?
No. WhatsApp says the face and fingerprint check happens entirely on your phone, and it can't access the biometric information your phone stores. WhatsApp only gets a yes or no from your phone's security system.
My verdict
Turn on app lock under Settings, Privacy and App lock, set it to lock quickly, and hide message previews so the lock means something. If you only want to hide a few conversations, use chat lock instead. Both take less than a minute and stop the most common privacy slip: someone picking up your unlocked phone.
Frequently asked questions
How do I lock WhatsApp with my fingerprint?
On Android go to Settings, Privacy, App lock and switch on the biometric option. On iPhone go to Settings, Privacy, App Lock and turn on Face ID or Touch ID.
Can I still get calls when WhatsApp is locked?
Yes. WhatsApp says you can still answer calls when app lock is on.
How do I lock WhatsApp Web?
Go to Settings, Privacy, App lock and set a password of 6 to 128 characters. Use Ctrl Alt L on Windows or Cmd Ctrl L on Mac to lock it instantly.
What's the difference between app lock and chat lock?
App lock locks the whole app. Chat lock hides chosen chats in a separate folder behind extra authentication.
