A thin film transistor array panel including a substrate, a plurality of first signal lines formed on the substrate, a plurality of second signal lines, insulated from the first signal lines, which are formed on the substrate and which define an area of a display area by traversing the first signal lines, a driver disposed on a peripheral area, a plurality of connection lines, disposed on the peripheral area, which couple the driver to each of the first signal lines, and an insulating layer which insulate the first signal lines from the connection lines. The insulating layer includes a plurality of contact holes, portions of the first signal lines and the connection lines are connected through the contact holes, and sizes of exposed portions of the first signal lines exposed through the contact holes increase as respective distances from the contact holes to the driver increase.