On Illegibility is a lecture performance on identification politics in the development and use of biometric technology such as facial recognition and fingerprint scanners. The lecture scrutinizes the algorithms that center certain bodies as a standard from which others are mere deviations, and traces how biometrics ultimately shape definitions of what a human being is. This lecture unpacks what it means to be legible in the eyes of the state and society, and looks into strategies built into “illegible” bodies and faces.