Some embodiments of the present disclosure provide an array substrate, a display panel and a display device. The array substrate includes a test circuit located in a non-display area, wherein the test circuit includes at least one stage of subcircuit, and the subcircuit includes at least one demux; except the first stage of subcircuit, the input ends of the demuxes in the subcircuit are connected with corresponding output ends of the demuxes in the previous stage of subcircuit; except the last stage of subcircuit, the output ends of the demuxes in the subcircuit are connected with corresponding input ends of the demuxes in the next stage of subcircuit; and the input end of the demux in the first stage of subcircuit is connected with a test terminal, and the output ends of the demuxes in the last stage of subcircuit are connected with signal lines in a display area.