A display device includes a plurality of pixels, a power supply, a voltmeter, and a timing controller. The power supply is configured to generate an initialization voltage to be supplied to a sensing pixel among the pixels. The voltmeter is configured to measure a first value of the initialization voltage supplied to the sensing pixel during an active period of a frame period and a second value of the initialization voltage supplied to the sensing pixel during a vertical blank period of the frame period. The timing controller is configured to generate rewrite image data that is supplied to the sensing pixel during the vertical blank period. The rewrite image data is generated from image data applied to the pixels during the active period and a difference between the first and second values.