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How does Apple’s FaceID on the iPhone X work?

It is likely that you’ve heard of Apple’s recent feature “FaceID”. This feature allows a user to unlock their phone or mobile apps using only their face as a form of biometric authentication. Users can ever authorize transactions on Apple Pay with FaceID. However, how does Apple’s FaceID work? What is actually happening behind the scenes when you show your face to your phone? In this post, we will explain how FaceID works behind the scenes.

Why is FaceID only on the iPhone X? What are the steps your iPhone X takes?

The iPhone X has unique sensors that are required for FaceID to work. On the top of the iPhone X screen, there is a proximity sensor, an ambient light sensor, a flood illuminator, an infrared dot projector, and an infrared camera. “Infrared” refers to a spectrum of light that is not visible to the human eye. FaceID only works on the iPhone X because only the iPhone X is equipped with these needed sensors.

To use FaceID, the process is initiated when a user lifts their phone and tilts it towards their face in order to look at the screen. The iPhoneX’s proximity sensor and ambient light sensor then examine how close your face is to the phone and how much light is in your environment. This information determines how much light the flood illuminator uses to illuminate your face. It should be noted that this “illumination” is done using infrared light, which is invisible to the human eye.

Next, the iPhoneX projects up to 30,000 infrared dots towards your face. The infrared camera on your iPhoneX is then able to read the unique pattern of these infrared dots on your face to create a 3D map of your face. This 3D map accounts for the area and depth of your unique facial features. Your iPhoneX then compares this 3D face map against previous 3D face map, and, if these two records pass, then the user is able to unlock their iPhoneX or app of interest.

Some interesting components of iPhoneX’s FaceID

It must be said that iPhoneX’s FaceID is supposed to be a very secure method for authentication. In fact, Apple claims that FaceID is more secure than Apple’s previous fingerprint authentication feature, TouchID. Apple claims that, while TouchID may allow unauthorized access to your phone in just 1 in 50,000 cases, FaceID may allow unauthorized access to your phone in only 1 in 1,000,000 cases. Also, FaceID adjusts its security depending on the situation. For example, if you are simply opening your phone for the third time in an hour, your 3D face map will not need to match your saved 3D face map as perfectly as if you were trying to use FaceID to make a several hundred dollar purchase using Apple Pay. Additionally, the iPhone X saves its 3D rendering of your face on its signature A11 Bionic Chip. This means that your 3D face map will never pass through any third party servers, and your FaceID data is thereby that much more secure.

Another interesting feature associated with FaceID is that this technology can work when you are wearing hats, scarves, and even sunglasses. This is convenient particularly in winter months when you may be bundled up from the cold but still in need of accessing your phone. Additionally, Apple includes an “attention aware” component when it scans a user’s face to make sure that their eyes are open and that they are looking at the iPhoneX. This helps prevent individuals from accessing your phone by using your face when you are sleeping.


Apples FaceID biometric authentication is definitely a useful and exciting feature from Apple. It makes your mobile usage more secure, and it also makes your mobile experience a lot more enjoyable. With FaceID, your transition between apps is made seamless, as you no longer have to manually type in your usernames and passwords. Now, you only have to show your face. Over the coming year, FaceID will become more widely used within industries that demand top safeguards for ensuring user authenticity, such as in mobile banking and mobile telemedicine.