Face ID is a facial scanning system that Apple implemented into the iPhone X as a biometric identity replacement for Touch ID. Apple claims there is one-in-a-million chance that Face ID will unlock with another person's face thanks to the use of seven different sensors attached to the front-facing camera. It will automatically scan and confirm your identity without you even having to press a button, which is good because Apple also got rid of the Home button in iPhone X.
What is Face ID
Face ID uses multiple neural networks that are built into the dual-core A11 bionic neural engine to process the facial recognition data.
It takes a mathematical model of your face and checks it against the original scan of your face that you first registered.
The information is stored on the A11 chip on your iPhone X and not sent to Apple's servers, so your facial identity is kept private.
It uses a Require Attention feature in order to work. That means you have to be looking at your iPhone for it to scan, You can't be asleep or looking away for it to unlock your iPhone.
What's this TrueDepth camera all about?
The TrueDepth camera is the hub of Face ID. Similar to the way Touch ID uses focused sensors on the Home button that takes a high-resolution picture of your fingerprint, the TrueDepth camera uses depth mapping to get a detailed picture of all of the features of your face. The TrueDepth camera is made up of eight different parts, which when used together, allow for the depth needed for proper facial scanning. The TrueDepth camera uses:
- 7PM camera
- Infrared camera
- Flood illuminator
- Front camera dot projector (30K dots)
- Proximity sensor
- Ambient light sensor
How does Face ID know it's really me?
Apple explained that the advanced scanning sensors in conjunction with the A11 bionic processor make it nigh-impossible for someone to spoof your facial scan. It doesn't work with photographs. It doesn't work while you're asleep. It doesn't even work with detailed silicon masks that look just like you. It works kinda like magic, only the effort that went into perfecting facial recognition is anything but magic.
What if I grow a beard, wear glasses, or change over time?
Face ID uses 30,000 infrared dot scanners and pushes then through that neural network mentioned above. It doesn't just do a quick image scan. It's not like Faces in the Photos app. It's much, much deeper.
It adapts to your facial changes over time. It learns your face. If you start wearing glasses (including sunglasses) or cut your hair. It will still identify your face. If you gain or lose weight or grow old, it will still know it's you.
If you wear a little or a lot of makeup, if you look like a completely different person when you wake up in the morning, it will still recognize the structure of your face, which doesn't change whether you're wearing makeup or not.
If you experience some complete facial change, like swelling or disfigurement due to an accident, or if the structure of your face changes due to facial reconstruction, you can re-scan your face for a new Face ID identification. These are more permanent changes, and not simply a matter of you looking different when you wake up in the morning.
How does Face ID work with identical twins?
It doesn't. Apple noted in its demo of Face ID that if you have an "evil twin" (in other words, identical twin), you're just going to have to use a passcode if you don't want that twin to access your iPhone.
If, however, you have a sibling with similar (but not identical) facial features, you should be OK. Apple's facial recognition technology is detailed enough to recognize even slight differences in faces.
What about people of color? Did Apple finally get facial recognition right?
We haven't heard any issues from our personal experiences with the iMore staff, nor have there been any complaints from the larger tech community about this particular issue.
How is 'Require Attention' supposed to work for people with facial quirks?
Apple's Require Attention feature means you have to be able to show the iPhone that you are aware of its scan by looking directly at it. This ensures that someone can't just scan your face while you're sleeping or looking away, unknowing that someone else has your iPhone. There are definitely people that won't be able to perform the actions required for Require Attention.
Apple included the ability to disable Require Attention in the Face ID and Passcode settings. For those with issues looking directly at their iPhone, you can disable Require Attention and still use Face ID.
Can more than one person register their face with Face ID?
Nope. Sorry. You and your spouse can't use Face ID on the same iPhone right now. It only registers one face. If you want to allow someone else to have access to your iPhone X, you'll just have to give them your passcode.
What does Face ID work with?
Face ID works with Apple Pay in participating retail stores and online. The same way you use Touch ID to pay for things at your local coffee shop or favorite online store, you can instead use Face ID.
Face ID also works with third-party apps that currently support Touch ID. Face ID code will simply replace Touch ID code. So all of your favorite Touch ID apps should also work with your facial imprint, too.
What about privacy concerns?
Similar to the way Touch ID keeps your fingerprint scan private and secure, a lot of work went into making sure that your facial scan privacy is protected. The information collected when your face is scanned goes directly into the A11 Bionic chip and stays there. It is never uploaded to Apple's servers and there is no possible way it could be. No one else has access to your facial scan but you.
As for someone being able to simply hold your iPhone up to your face against your will to unlock it, Face ID requires Attention Awareness, which means you have to be looking at your iPhone to trigger the unlock. Sure, there are circumstances under which you could be forced to unlock your iPhone with your face under duress, but the same goes for Touch ID, and for that matter, your passcode (though the U.S. government can't legally force you to give up your passcode). Basically, you can be physically forced to do a lot. What you can do, if you sense that the security of your locked iPhone is about to be forcibly compromised, is quickly press the Side button (also known as the Sleep/Wake button) to trigger SOS/Power Off. You don't have to call emergency or power off your iPhone, but it will automatically disable Face ID until you enter your passcode.
If you're worried about someone spoofing your face to unlock your iPhone, you should stop. Though some videos have come out claiming to have been able to spoof Face ID, they've been discredited. Face ID is very secure and works incredibly well to identify your face and yours alone.
Even if someone were able to successfully create a very expensive detailed mask that could spoof Face ID and managed to steal your iPhone, you'd probably have had enough time to simply wipe it remotely before anyone could get a chance to access your data.
I'm not saying that Face ID is lock-down secure and that no one will ever be able to access your iPhone as long as you use it. I'm just saying that there is a lot of fear surrounding security and privacy of Face ID that is unfounded. Be careful, but don't be fearful.
iMore Editor in Chief Rene Ritchie wrote a thoughtful editorial on Face ID and why most concerns are simply fear, uncertainty, and doubt gone rampant.
More on Face ID
If you're wondering how to set up and start using Face ID and all of its features, we've got you covered.
Updated April 2018: Added links to support articles for Face ID.