A neural network may implement a face detection process on a mobile device or computer system. An image captured using a camera on the device may be processed using the face detection process. The face detection process may provide a bounding box for the face detected in the image. The face detected in the image may have any orientation. The face detected in the image may include either a whole face of the user or only a partial face of the user. The face detection process may provide face detection that is substantially invariant to exposure in the captured image. The face may also be detected over a wide range of distances between the camera and the face of the user.