What Face ID does and doesn't protect

Face ID is a biometric lock that replaces typing a password when you open an app. Instead of remembering a code, your phone scans your face and unlocks the app if it matches the face data stored on your device. This works on iPhones and iPads with Face ID hardware, and on some Android phones with similar facial recognition.

Face ID makes it harder for someone who picks up your phone to access your apps, because they would need your actual face, not just your password. But it does not encrypt the data inside the app itself — it only controls who can open the door. If an app has a security flaw or sends data over an unencrypted connection, Face ID will not stop that.

Face ID also does not work if your phone is stolen and the thief resets it, or if someone has your password and logs in from a different device. It is one layer of protection, not a complete security system.

Key Takeaways

  • Face ID must be set up on your device first — go to Settings, then Biometric settings (Face ID on iPhone, Face Unlock or Biometric on Android), and follow the on-screen scan.
  • Most apps that support Face ID have a toggle in their own settings menu, usually under Security or Privacy, that you turn on yourself.
  • Some apps require you to set a password or PIN before they will let you use Face ID as an unlock method.
  • Face ID works only on the device where you set it up — if you log into the same app on a different phone, you will need to set up Face ID again on that device.

Setting up Face ID on your device first

Before any app can use Face ID, your phone or tablet must have Face ID enabled. On an iPhone or iPad, open Settings, tap Face ID & Passcode (or just Face ID on newer models), and enter your passcode. Tap Set Up an Additional Appearance or Enroll Face if this is your first time, then follow the on-screen instructions to scan your face. The scan takes about 10 seconds and you will be asked to move your head slightly so the camera can capture your face from different angles.

On Android, the process varies by manufacturer. Open Settings, look for Biometric or Security, then find Face Unlock or Face Recognition. Tap Set Up or Enroll, then hold your phone at arm's length and let the camera scan your face. Some Android phones ask you to scan your face twice — once in bright light and once in dim light — to make the recognition more reliable.

After Face ID is set up on your device, you can turn it on in individual apps. Your device will not automatically enable Face ID in every app — you have to choose which apps use it.

Turning on Face ID in individual apps

Most apps that support Face ID have a setting you control yourself. Open the app, go to Settings or Preferences (usually a gear icon or three horizontal lines), then look for Security, Privacy, or Biometric. You should see a toggle or checkbox for Face ID, Face Unlock, or Biometric Authentication. Turn it on.

Some apps ask you to confirm your password or PIN the first time you enable Face ID. This is normal — the app is verifying that you are the account holder before it links your face to your account. Type your password when prompted, then Face ID will be active for that app.

If you do not see a Face ID option in an app's settings, the app does not support it yet. Developers have to build Face ID support into their apps — it is not automatic. You can check the app's support page or contact the developer to ask if they plan to add it.

Apps that commonly support Face ID

Banking apps like Chase, Bank of America, and Wells Fargo typically support Face ID. Password managers like 1Password, Bitwarden, and LastPass use it to unlock your stored passwords. Payment apps like PayPal, Venmo, and Apple Pay often have Face ID as an option. Social media apps like Instagram, Facebook, and Twitter may support it, though not all do.

The best way to know if your specific app supports Face ID is to open it, go to settings, and look for the option. If it is there, you can turn it on. If it is not, the app either does not support it or the developer has not enabled it yet.

What to do if Face ID stops working in an app

If Face ID worked before but suddenly stops, the most common fix is to turn it off and back on. Open the app, go to Settings, find the Face ID toggle, turn it off, wait a few seconds, then turn it back on. You may need to enter your password again.

If that does not work, try updating the app. Open your device's app store (App Store on iPhone, Google Play on Android), search for the app, and tap Update if one is available. Developers often fix Face ID bugs in updates.

If Face ID still does not work after updating, try unlocking your device with Face ID first. Open Settings, go to Face ID settings, and scan your face again to make sure your device still recognizes you. If device-level Face ID is broken, app-level Face ID will not work either. If your device Face ID is fine but the app still fails, uninstall and reinstall the app as a last resort.

Face ID on multiple devices

Face ID is tied to the specific device where you set it up. If you log into the same app on a different phone or tablet, you will need to set up Face ID on that device too. This means scanning your face in that device's Face ID settings first, then turning on Face ID in the app.

This is actually a security feature — it means someone cannot use your account on their phone just because they know your password. They would need access to a device where you have already set up Face ID, or they would have to use your password every time.

If you get a new phone and want to use Face ID on your apps there, set up Face ID on the new device first, then log into each app and turn on Face ID in its settings.

Privacy and security considerations

Your face data stays on your device — it does not get sent to the app developer or stored in the cloud (unless you choose to back up your device, in which case Apple or Google encrypts it). The app only receives a yes-or-no answer: "This is the right face" or "This is not the right face." The app never sees the actual scan.

This means the app cannot use your face data for anything else, like identifying you in photos or selling your biometric information. However, the app can still collect other data about you — your location, your activity, your contacts — depending on what permissions you gave it. Face ID only controls access to the app itself, not what the app does with your data once you are inside.

If you are concerned about an app's data practices, check its privacy policy before turning on Face ID. Face ID makes the app more convenient, but it does not make a privacy-invasive app safer.

Frequently Asked Questions

Can someone unlock my app with Face ID if they have a photo of me?

No. Face ID uses depth-sensing technology to detect a real face, not a flat image. It can tell the difference between a photo and a living person. However, identical twins or very close family members might be able to unlock Face ID in rare cases, which is why some apps ask for a password as a backup.

What if I change my appearance — will Face ID still work?

Face ID adapts to gradual changes like growing a beard, wearing glasses, or getting a haircut. If you make a major change like shaving your head or having surgery, you may need to re-enroll your face in your device settings. Most of the time, Face ID adjusts on its own.

Does Face ID work if I am wearing a mask?

On newer iPhones (iPhone 15 and later), Face ID works with a mask covering your nose and mouth. On older iPhones, Face ID does not work with a mask. On Android, it depends on the phone model — some support masked face recognition and some do not. Check your device manual or settings to see if yours does.

Can I use Face ID if I have a visual impairment?

Face ID requires your device to see your face clearly, so it may not work if you have severe vision loss that affects your face. However, you can always use your password or PIN instead. Most apps that support Face ID also let you turn it off and use a traditional password.

What happens to Face ID if I disable it on my device?

If you turn off Face ID in your device settings, it will stop working in all apps. You will need to use passwords to unlock each app instead. You can turn device-level Face ID back on anytime by going to your biometric settings and re-enrolling your face.