A display device includes a driving controller, a display panel, and an emission driver. The driving controller generates a second clock signal having second pulses in response to a first clock signal having first pulses from an external device. The display panel includes pixels. The emission driver generates an emission signal having third pulses in response to the second clock signal and applies the emission signal to the pixels. The driving controller compares a number of the first pulses and a number of the second pulses, with a first reference value, and a second reference value, and sets a compensation value of the number of the second pulses, and the driving controller compensates for the second clock signal by adjusting the number of the second pulses existing in one horizontal time based on the compensation value in a vertical blank period of the frame period.