A gate driver has a plurality of stages for outputting a gate signal for image at a time of display driving and outputting a gate signal for sensing at a time of sensing driving that follows the display driving. Each of the stages includes a pixel line selecting unit charging an M node with a first preceding stage carry signal according to a pixel line selection signal of a gate-on voltage during the display driving and charging a Q node with a first high-potential power supply voltage according to a sensing start signal of a gate-on voltage and a charged voltage of the M node during the sensing driving, and an output unit outputting a scan clock of a gate-on voltage as the gate signal for sensing while the Q node maintains a charged state on the sensing driving, wherein the first high-potential power supply voltage is higher at the time of the sensing driving than at the time of the display driving.