A display device includes a substrate including a display area and a non-display area. The display device further includes a plurality of pixels in the display area of the substrate. The display device additionally includes a plurality of gate lines and a plurality of data lines respectively connected to the plurality of pixels. The display device further includes a plurality of insulative step portions disposed in the non-display area of the substrate and arranged in a first direction parallel to sides of the display area. The display device further includes a crack detection line in the non-display area and extending primarily in the first direction. The crack detection line includes a first portion which does not overlap the plurality of insulative step portions, and a second portion overlapping each of the insulative step portions.