An optical receiver includes a reception module, a first detector, a second detector, a shift module, a first extraction module, and a second extraction module. The reception module receives a frame. The first detector detects a head position of a first layer, the head position being included in the frame. The second detector detects a head position of a second layer, the head position being included in the frame. The shift module shifts the frame so that the head position of the first layer and the head position of the second layer are located at respective predetermined positions. The first extraction module extracts a header of the first layer from the frame after the frame is shifted. The second extraction module extracts a header of the second layer from the frame after the frame is shifted.