A display device including a substrate having a display area and a non-display area outside the display area, a plurality of pixels disposed in the display area on the substrate, a plurality of data lines connected to the pixels, a first crack detection line disposed in the non-display area on the substrate, the first crack detection line being electrically connected to at least one of the data lines, and a second crack detection line disposed in the non-display area outside the first crack detection line, the second crack detection line being electrically connected to at least one of the data lines.