A display device includes a substrate, a plurality of sub-pixels and a covering layer. The substrate includes a display area and a peripheral area. The peripheral area is adjacent to the display area. The sub-pixels are disposed in the display area and arranged along a first direction. The sub-pixels have a first color, and two adjacent one of the sub-pixels have a first pixel pitch along the first direction. The covering layer is disposed in the peripheral area and has a first recess. The first recess has a first portion extended along a second direction perpendicular to the first direction. The first portion has a first width along the first direction. A ratio of the first width to the first pixel pitch is greater than or equal to 0.05 and less than or equal to 0.7.