Face ID turns your face into your iPhone's password

Face ID is Apple's facial recognition system that unlocks your iPhone, approves purchases, and signs you into apps by scanning your face. You set it up once in Settings, and then your phone recognizes you without typing a code. It works in most lighting and from different angles, though it won't work if you're wearing a ski mask or if someone is holding the phone at an extreme angle.

The feature lives on iPhones with a notch or Dynamic Island at the top of the screen — that's iPhone X and newer models. If you have an older iPhone with a home button, your phone uses Touch ID (fingerprint) instead, and Face ID isn't available.

Key Takeaways

  • Face ID setup takes about two minutes and happens in Settings under Face ID & Passcode, where you'll scan your face twice from different angles.
  • You must have a passcode set before you can turn on Face ID, because the passcode is your backup if Face ID fails.
  • Face ID data stays encrypted on your phone and never leaves it — Apple's servers don't store your face scan.
  • You can add a second face scan (called an "alternate appearance") if you want to let someone else unlock your phone, or to account for major changes to your own appearance.
  • Face ID works even when you're wearing glasses or a hat, but not when your eyes are covered or when the camera lens is dirty.

What you need before you start

Your iPhone must be running iOS 11.3 or later. You can check this by opening Settings, tapping General, then About, and looking at the "Software Version" line. Most iPhones update automatically, so unless you've deliberately turned off updates, you're probably current.

You also need a passcode already set up. If you don't have one, Face ID won't let you proceed — the passcode is the safety net if Face ID stops working or if you're in a situation where you can't use your face to unlock. To add a passcode first, go to Settings, tap Face ID & Passcode, then Create a Passcode, and follow the prompts.

The step-by-step setup process

Open Settings and scroll down to find Face ID & Passcode. Tap it, then enter your current passcode when prompted. Tap "Set Up Face ID" (or "Set Up an Alternate Appearance" if you're adding a second face).

Hold your iPhone about 10 to 20 inches from your face, centered in the circle on the screen. The phone will ask you to move your head slowly in a circle so the camera can map the contours of your face from different angles. This first scan takes about 15 seconds. When it finishes, you'll see "First Face Scan Complete."

Tap "Continue" and repeat the process. The second scan captures your face from slightly different angles and lighting conditions, which makes Face ID more reliable in real-world situations. When both scans finish, you'll see "Face ID is now set up" and a checkmark. Tap "Done," and you're finished.

How Face ID actually works on your phone

When you try to unlock your iPhone, the TrueDepth camera at the top of the screen projects thousands of invisible dots onto your face and reads them back. It compares that map to the two scans you created during setup. If they match closely enough, the phone unlocks. The whole process takes less than a second.

Face ID doesn't store a photo of your face. Instead, it stores mathematical data about your face's shape — the distance between your eyes, the curve of your nose, the structure of your chin. That data is encrypted and locked to your phone's secure chip. Apple's servers never see it, and it doesn't sync to iCloud or any other cloud service. If someone steals your phone, they can't extract your face data from it.

The system is designed to work with glasses, sunglasses, hats, and scarves. It adapts over time — if you grow a beard or change your hairstyle, Face ID learns the change and keeps working. However, it won't work if your eyes are covered (like with a ski mask or a medical mask that covers your eyes), or if the TrueDepth camera is blocked by dirt, a screen protector, or a case that covers the notch.

What to do if Face ID isn't working

If Face ID stops recognizing you, first check that the camera area at the top of your phone is clean. Wipe it gently with a soft, dry cloth. If the problem persists, try unlocking with your passcode instead, then go back to Settings, Face ID & Passcode, and delete the face scan by tapping "Delete Face ID." Set it up again from scratch, making sure you're in good lighting and holding the phone at a normal distance.

If Face ID fails repeatedly even after a fresh setup, the TrueDepth camera itself may be damaged. You can still use your passcode to unlock your phone, but you'll need to visit an Apple Store or authorized repair center to have the camera checked. In the meantime, Face ID will simply fall back to asking for your passcode, so your phone remains secure.

Adding a second face or letting someone else unlock your phone

You can store two different faces on your iPhone. This is useful if you want to let a family member unlock your phone, or if you want to account for a major change in your appearance (like after surgery or significant weight loss). Go to Settings, Face ID & Passcode, enter your passcode, and tap "Set Up an Alternate Appearance." Follow the same scanning process as before.

If you add a second face, both faces will unlock your phone equally. There's no way to set one face as "primary" or to see which face unlocked your phone after the fact. If you later want to remove the second face, go back to Face ID & Passcode and tap "Delete Alternate Appearance."

Privacy and security considerations

Face ID data never leaves your phone. It's stored in a secure area of your iPhone's processor called the Secure Enclave, which is separate from the rest of the operating system. Even if someone hacks your phone's software, they can't access the face data stored there. Apple itself cannot see your face scan, and law enforcement cannot force Apple to unlock your phone using Face ID data because Apple doesn't have it.

However, law enforcement can compel you to unlock your phone with your face in some situations — the legal rules vary by country and state. Your passcode has stronger legal protection in many places because it's considered something you know, whereas your face is something you are. If you're concerned about this, you can disable Face ID and use only your passcode by going to Settings, Face ID & Passcode, and toggling off the features you don't want (like "iPhone Unlock" or "Apple Pay").

Frequently Asked Questions

Does Face ID work in the dark or with sunglasses on?

Face ID works in low light because the TrueDepth camera projects its own infrared light — it doesn't rely on room lighting. Regular sunglasses usually work fine, but very dark or reflective sunglasses may block the camera's view. You can test this by trying to unlock your phone while wearing them. If it fails, you'll fall back to your passcode.

Can someone unlock my iPhone by holding it up to my face while I'm sleeping?

No. Face ID requires your eyes to be open and looking at the phone. If your eyes are closed or if you're not looking at the screen, Face ID will fail and ask for your passcode instead. This is a deliberate security feature.

What happens if I change my appearance a lot, like with different wigs or makeup?

Face ID adapts to gradual changes like growing a beard or changing your hairstyle. However, extreme changes like a full wig or heavy theatrical makeup might confuse it. If Face ID stops working reliably, you can delete it and set it up again, or add an alternate appearance that captures you in that look.

Is Face ID less secure than a passcode?

Face ID and passcodes offer different kinds of security. A passcode is something only you know; Face ID is something only you are. In practice, Face ID is very difficult to fool — it's designed to reject photos, masks, and even high-quality 3D models of your face. However, a passcode is your legal backup, and some people prefer the certainty of typing something they control.

Can I use Face ID for apps and payments, or just to unlock my phone?

Face ID can unlock your phone, approve App Store purchases, sign you into banking apps, and authorize Apple Pay transactions. Each app decides whether to support Face ID. You can turn off Face ID for specific features in Settings — for example, you might allow it for unlocking but not for payments. Go to Face ID & Passcode to see all the toggles available.