A private message popped up on your lock screen in front of someone

It happens at the worst moment. Your phone is face-up on the meeting table, on the dinner table at your parents’ house, or in your hand while you show a colleague a photo. A message arrives, and the first two lines appear on the screen for everyone to read: a medical result, a message from a date, a bank alert, a friend’s frank opinion of the person sitting next to you. You can’t unsend what was seen. You can make sure it’s the last time.

What to do now

1. Lock the phone or turn it face-down. A quick press of the side button clears the screen. You don’t owe anyone an explanation.

2. Don’t scramble to delete. Deleting the message in front of people draws more attention than the notification did. Deal with it later.

3. If it was seen and it matters, decide whether to address it. Sometimes a short “that was private” is better than pretending nothing happened. Sometimes it’s best left. You know the people involved.

4. Change your notification settings today. It takes a minute.

• On iPhone: Settings, then Notifications, then Show Previews, then When Unlocked.
• On Android: Settings, then Notifications, then Notifications on lock screen, and turn off Show sensitive content. Menu names vary a little between phone makers.

5. Set individual apps. Messaging, email, dating, banking and health apps are the usual culprits. Both phones let you choose a different preview setting for each app. The full steps are in hiding message previews on your lock screen.

What doesn’t help

• Turning notifications off entirely. You’ll miss things that matter. Hiding the content is enough.
• Keeping the phone face-down forever. It works until the one time you forget.
• Relying on the screen timing out quickly. Notifications light up a locked screen anyway.

Habits that help

• Before a presentation or screen share, turn on do not disturb or a focus mode. On iPhone, also turn off notifications during screen sharing in Notifications settings. See sharing your screen on a video call.
• Before handing your phone to someone, the same applies: a message can arrive while they’re looking at your photos.
• Ask close friends to avoid putting sensitive details in the first line of a message, if it keeps happening.

Other places private content can surface

Notifications aren’t the only way private things appear on a screen others can see:

• A smartwatch on your wrist can show the full text of a message to whoever is next to you. Watches usually follow the phone’s preview settings, but check the watch app.
• Home screen widgets can show recent photos, messages or calendar entries. Remove the ones that show personal content.
• Smart suggestions and memories can put a private photo on the lock screen or in a slideshow. See a private photo on your lock screen.
• Shared tablets and computers signed in to your account can show the same notifications.

If someone reads your phone on purpose

Hidden previews protect against glances. If someone picks up your phone to read your notifications, or knows your PIN, that’s a different problem. See your partner knows your PIN.

Where a vault helps

Notifications are about messages arriving. Photos have a similar problem: a private picture can appear in a memory, a widget or your photo grid when someone’s looking. Silo, coming soon to iPhone and Android, keeps imported photos inside its encrypted vault, and its app-switcher cover hides the screen when you switch apps.