Yes, the "Smart Lock" feature included in Android OS 4 and above includes a face recognition feature. Although its use is limited to unlocking, just turn your face to the Android device to complete the authentication. It is faster than fingerprint authentication and pattern input, so it is recommended for those who want to reduce the trouble of unlocking as much as possible.
To enable face recognition, open the screen in the order of "Settings" → "Lock screen and security" → "Smart Lock" (the item name may differ slightly depending on the version of the terminal or system), and then "Recognize". Tap the Finished Face item. If you register your face according to the instructions on the screen, you can unlock it by turning your face to the Android device when the lock screen is displayed.
However, this face recognition is not perfect, and multiple face photos must be registered in order to improve the recognition accuracy. If you do not increase the variation of the face such as bright place, dim place, presence of glasses and mustache, authentication will often fail, so tap the "recognized face" item to "improve the accuracy of face recognition". Open and shoot the face in various states.
In addition, since faces with a certain percentage hidden cannot be registered, face recognition with the mask on will not work. As you are warned on the registration screen that "face recognition is less secure than patterns, PINs, and passwords," other authentication methods are said to be more secure. You should use it carefully, considering that there is a risk that even people with similar faces such as family members will be authenticated.
