Abstract: An end of line seat tester for adjustable seats, comprising an array of optical sensors for sensing and measuring the physical adjustment of seat components such as a headrest, seatback or seat cushion. In a preferred form the optical sensor array is combined in closed-loop fashion with an internal function tester connected through a powered seat control module by tether to monitor the internal function of the power adjustment mechanisms. The external, optical sensing of the seat adjustments can be used to verify the internal testing of the seat adjustment mechanisms, both as to static adjusted positions and real time adjustment motion.