Display device including a fan-out unit and test line in the peripheral area

A display device, comprising:

• a substrate including a display area and a peripheral area surrounding the display area, wherein the display area has a non-quadrangular shape and the peripheral area is divided into a first peripheral area and a second peripheral area with respect to a reference axis passing through a center of the display area;
• a plurality of data lines extending in a first direction in the display area;
• a fan-out unit arranged in the first peripheral area and comprising a plurality of wirings connected to the plurality of data lines, respectively;
• a test line arranged in the peripheral area;
• a demultiplexer arranged in the peripheral area;
• and
• a common power supply line arranged in the peripheral area, wherein each of a portion of the test line, a portion of the demultiplexer, and a portion of the common power supply line overlaps the fan-out unit in the first peripheral area.