A display device includes a display panel having a display area and pixels at the display area, a power supply configured to supply a first power source voltage to the pixels through a first power line extending to the display area, and to supply a second power source voltage lower than the first power source voltage to the pixels through a second power line including first and second side power lines extending in first and second peripheral areas located at first and second sides of the display area of the display panel, a sensor configured to detect first and second detection values corresponding to currents of the first and second side power lines, and a controller configured to control an operation of the power supply, based on a difference between the first detection value and the second detection value.