To provide a display device which includes a touch sensor and a large number of pixels and in which a driver circuit of a display portion and a driver circuit of a touch sensor are formed in one IC. The display device includes the display portion, the touch sensor, and a plurality of ICs. The plurality of ICs each include a first circuit. One of the plurality of ICs includes a second circuit and a third circuit. The first circuit has a function of outputting a video signal to the display portion. The second circuit has a function of outputting a signal for driving a sensor element included in the touch sensor. The third circuit has a function of converting an analog signal output from the sensor element into a digital signal.