A display device includes: a pixel connected to each of a first scan line, a second scan line, and a data line; a scan driver supplying a first scan signal to the first scan line and a second scan signal to the second scan line; a controller dividing one frame period into an active period and a blank period and generating a count signal in which a time duration of the blank period is counted and a power control signal; a data driver supplying a data signal to the data line; and a power supply controlling a source driving voltage supplied to the data driver according to a duration of the blank period based on the power control signal. When the count signal reaches a reference value, the controller supplies a start signal for output of the first scan signal to the scan driver.