Provided are a gate driver and a display device. A low-resolution area is disposed in a portion of an active area, and an optical sensor is disposed on a side of the low-resolution area opposite to a surface of the low-resolution area on which an image is displayed, such that the display device displays images on the low-resolution area and performs sensing using the optical sensor. The low-resolution area and a high-resolution area surrounding the low-resolution area are driven using different gate lines. Image compensation for the low-resolution area is easily performed to reduce or remove the difference in the image quality between the low-resolution area and the surrounding areas.