Disclosed herein are a display device, an apparatus for testing a display device, and a method for testing a display device. A display device includes a first substrate having a display area and a non-display area defined thereon, the non-display area being on an outer side of the display area. The non-display area may include a plurality of test pads and a first dummy thin-film transistor electrically connected to the test pads. The first dummy thin-film transistor includes a dummy gate electrode, and a dummy source electrode and a dummy drain electrode insulated from the gate electrode and spaced apart from each other. A bending area is defined on the first substrate that at least partially traverses the display area and the non-display area, the bending area overlaps the first dummy thin-film transistor.