Disclosed is a display device having a display panel that includes a plurality of pixels in a display area, each pixel including a first thin film transistor (TFT); a plurality of pads in a non-display area outside the display area that provide operating signals to the plurality of pixels in the display area, each pad including a first signal line running toward the display area and a second signal line running toward an outer edge of the display panel, with each pad disposed between the first and second signal lines; and an extension line crossing one or more of second signal lines of the plurality of pads, two ends of the extension line running toward the outer edge of the display panel, wherein each of the one or more of second signal lines of the plurality of pads includes an active layer of a second TFT.