The present disclosure discloses a gate driver, an array substrate, a display panel and a display device so as to address problems in the gate driver that some shift register units become abnormal so that a succeeding shift register unit depending upon the shift register unit may not be triggered and consequently the entire GOA circuit may operate improperly and even become inoperative. The gate driver includes N shift register units, each of which is connected with respective one of N gate lines of a display panel, and a plurality of gate units. While a gate unit is enabled, the gate unit is configured to provide a current gate line with an output signal of a corresponding shift register unit connected to a preceding gate line and/or a corresponding shift register unit connected to a succeeding gate line.