Embodiments of the present disclosure relate to a display device and a driving method thereof, and the display device includes a demultiplexer connected to a first data line and transferring a data signal from the first data line to a plurality of second data lines during a data writing period of one frame, a compensator calculating an on-pixel ratio (OPR) using input data in the one frame and generating compensation data corresponding to a calculated OPR, and a data driver supplying the data signal to the first data line using the input data during the data writing period, and supplying a compensation data signal to the first data line using the compensation data in a blank period of the one frame, and the demultiplexer supplies the compensation data signal from the first data line to a second data line during the blank period.