An array substrate, a mask plate, a display panel and a display device. The array substrate includes a light-emitting layer, and the light-emitting layer includes a first light-emitting area, a second light-emitting area, and a third light-emitting area, and the second light-emitting area is located between the first light-emitting area and the third light-emitting area; The first light emitting area includes a plurality of first pixel repeating units, the second light emitting area includes a plurality of second pixel repeating units, the third light emitting area includes a plurality of third pixel repeating units, and the first pixel repeating The unit, the second pixel repeating unit and the third pixel repeating unit respectively include n pixels, n≥1 and n is an integer, and the pixel density of the third light-emitting area is smaller than the pixel density of the first light-emitting area, wherein The distance between the central axes of the adjacent second pixel repeating units is smaller than the distance between the central axes of the adjacent third pixel repeating units.