Chip-on-film package, display panel, and display device

A chip-on-film package comprising:

• a base substrate on which a first pad region extends on a first side defining one side of the base substrate, a second pad region extending on a second side defining an opposite side of the base substrate to the one side of the base substrate, and a third region located between the first pad region and the second pad region are defined;
• a dummy pad disposed on the first pad region;
• a plurality of input pads disposed on the first pad region;
• a plurality of output pads disposed on the second pad region;
• a first detection line disposed on the base substrate, wherein the first detection line includes a first sub-detection line connected between a first input pad of the input pads and a first output pad of the output pads, a second sub-detection line connected between a second input pad of the input pads and a second output pad of the output pads, a third sub-detection line connected between the second sub-detection line and a third output pad of the output pads, a fourth sub-detection line connected between a third input pad of the input pads and a fourth output pad of the output pads, and a fifth sub-detection line connected between a fourth input pad of the input pads and the fourth sub-detection line, the first output pad being connected to the third output pad in the second pad region, and the second output pad being connected to the fourth output pad in the second pad region,
• a second detection line disposed on the base substrate, wherein the second detection line is connected between the dummy pad and the first sub-detection line.