A display device includes a substrate, one line on the substrate, the one line extending from a peripheral region through a display region, pixels on the display region, the pixels being connected to the one line, an outer line on the peripheral region, the outer line being connected to the one line during a short circuit test process that detects a position of a short circuit defect, an electrostatic protection resistor on the peripheral region, the electrostatic protection resistor being connected to the outer line, a pad on the peripheral region, the pad being connected to the outer line through the electrostatic protection resistor, a short circuit test signal being applied to the pad during the short circuit test process, and a bypass line connecting a node between the pad and the electrostatic protection resistor to the outer line.