Stop WhatsApp Snooping: Linked Devices, Backups and the Lock Screen

Where snooping on WhatsApp really happens

People worried that someone is reading their WhatsApp often picture hacking. The reality is usually more ordinary. Someone scanned a QR code on your phone months ago and a browser tab has been mirroring your chats since. Or they know your passcode. Or your lock screen shows every message in full to whoever is sitting across the table.

End-to-end encryption means WhatsApp itself, your mobile network and anyone on the same Wi-Fi can’t read messages as they travel. It doesn’t help once a message is displayed on a device that someone else can see or use. So the work is on those devices, starting with the one route that leaves the clearest trace.

Step 1: check which devices can read your chats

WhatsApp lets you use your account on up to four linked devices alongside your phone: browsers, desktop apps, tablets and a second phone. Each of them receives your new messages in real time. They keep working even when your phone is off. That is useful, and it is also the most common way people read a partner’s or family member’s chats. Linking takes a few seconds with the phone in hand, and nothing on the phone’s home screen shows it afterwards.

Open the list: Settings › Linked devices on iPhone, or the ⋮ menu › Linked devices on Android. For each entry, ask whether it’s a device you own, and whether the last-active time matches when you used it. Tap anything that fails either test and choose Log out. It stops receiving messages straight away. It can’t be relinked without your phone scanning a new code.

Signs a linked device is already reading along

A linked session leaves small traces on your own phone. Chats appear as read when you haven’t opened them, because the message was opened on the other device. Notifications you expected never appear, for the same reason. Someone repeats details you’ve only ever written in WhatsApp. None of these proves anything on its own, since a notification can also be dismissed by a watch. Together with an entry you don’t recognise in the list, they are about as clear as the evidence gets.

Step 2: lock WhatsApp itself with your face or fingerprint

Your phone’s passcode is the weakest link if someone in your home knows it, and many people’s partners and children do. WhatsApp’s own lock adds a second check. With it on, opening WhatsApp needs your face or fingerprint, even on an unlocked phone.

• iPhone: WhatsApp Settings › Privacy › Screen lock › Require Face ID (or Touch ID).
• Android: WhatsApp Settings › Privacy › App lock › Unlock with biometric.

Choose Immediately. The one-minute and longer delays exist for convenience, but they’re exactly the window a snooper needs when you step away. Then check your phone’s own biometric settings. If someone else’s face has been added as an alternate appearance, or their fingerprint enrolled, the app lock opens for them too. On Android the lock falls back to the phone’s own screen lock if biometrics fail, so a known PIN still gets through. The lock is a strong deterrent, but not a vault.

Step 3: lock and hide the chats that matter most

Chat lock moves individual conversations into a separate Locked chats folder that opens only with your biometrics or a code. Long-press a chat and choose Lock chat, or open the chat’s info screen and find Chat lock. Their notifications change too: instead of the sender and text, you see only that there’s a new message.

The secret code, added in late 2023, goes further. You can set a code for the Locked chats folder that is different from your phone’s passcode, and hide the folder completely. The chat list then shows no sign it exists, and you open it by typing the code into the search bar. This matters in the situation where it’s most needed: someone who knows your phone passcode and looks through your WhatsApp while you’re out of the room.

Step 4: stop the lock screen giving messages away

Of all the ways WhatsApp messages are read by the wrong person, a notification on a phone lying face up is the simplest. It needs no access at all. Two layers control it: the phone’s notification settings and WhatsApp’s own.

On an iPhone, the best single change is Settings › Notifications › Show Previews › When Unlocked. Previews then appear only after Face ID recognises you, so glancing at your own phone still shows the text and a passer-by sees only “Notification”. On Android, the setting to hide sensitive content on the lock screen is under the phone’s notification settings. The exact wording varies between Samsung, Pixel and other makers. WhatsApp’s own notification settings can turn previews off for WhatsApp alone. Paired smartwatches have separate notification settings, and they are often forgotten.

Step 5: protect the backup, the copy nobody thinks about

Your chat history is backed up to Google on Android or iCloud on iPhone, usually every night. Without extra protection, that backup is protected by your Google or Apple account. If someone else can sign in to that account, it becomes part of your attack surface. This is typical of a shared family login, or an account a former partner set up for you.

End-to-end encrypted backup closes this. Go to Settings › Chats › Chat backup › End-to-end encrypted backup. You choose how to lock it: a password, a 64-digit key, or, as WhatsApp began rolling out in October 2025, a passkey that uses your face, fingerprint or screen lock. Once on, neither WhatsApp nor Google nor Apple can read the backup. Restoring it on a new phone needs the password, key or passkey as well as your phone number. Lose all of them and the backup is lost too, so store a password or key where only you can reach it.

While you are there, look at the account itself. Change the password on your Google or Apple account if anyone else might know it, and check which devices are signed in to it.

Step 6: protect sensitive groups from the other end

Some snooping happens through the people you are talking to: a chat exported and passed on, or media from a sensitive group saved automatically into someone’s photo gallery. WhatsApp’s Advanced Chat Privacy, launched in April 2025, is a per-chat setting for this. Tap the chat or group name, then Advanced chat privacy. With it on, nobody in the chat can export it, media isn’t saved automatically to their phones, and messages can’t be used with AI features.

WhatsApp describes this as a first version, and it has clear limits. It doesn’t stop screenshots or a photo of the screen, and any member can turn it back off. It is for groups where people don’t all know one another but the subject is sensitive. It won’t protect you from someone who has access to your own phone.

Two smaller settings are worth a moment while you’re in Privacy. Disappearing messages reduce how much history exists to be read at all. Privacy checkup walks through who can see your profile photo, last seen, status and group invitations. Finally, turn on two-step verification under Account. It doesn’t stop snooping, but it stops the next step up, a full takeover. Our guide to recovering a hacked WhatsApp account explains why.

What no WhatsApp setting can fix

Every setting above assumes the phone is yours alone apart from WhatsApp. If monitoring software is installed on the device, it can read the screen or notifications after WhatsApp has decrypted them. No app lock, chat lock or encrypted backup prevents that. The signs are different — unexplained apps with broad permissions, accessibility services you didn’t turn on, device-admin apps. So is the fix. Our guide to stalkerware-proofing your phone covers the checks, and the risk that removing such an app alerts whoever installed it.

Nor can any setting stop the person you’re writing to from showing your messages to someone else. Disappearing messages and view-once media reduce what’s left lying around, but a screenshot or a second phone pointed at the screen defeats both.

Keep it secure: a five-minute monthly routine

Settings drift. A laptop gets linked for a video call and forgotten. A new face is added to Face ID “just so I can unlock it for you”. A backup gets switched off to free up space. A short routine once a month catches these before they matter: Linked devices, app lock, the phone’s biometric list, backup encryption, two-step verification and the Privacy checkup.

How this page was put together

The settings on this page were checked in September 2026 against WhatsApp’s help centre and its official announcements. Those include Advanced Chat Privacy (April 2025), the chat lock secret code (November 2023) and passkey-encrypted backups (October 2025). Where iPhone and Android differ, both are given. Phone makers word notification settings differently, so treat those labels as a guide.

We have not tested any monitoring or snooping tools against WhatsApp, and this page recommends none. For how our guides are researched and corrected, see our editorial standards.