Durable and scratch resistant articles including low-reflectance optical coating with gradient portion. In some embodiments, an article comprises: a substrate comprising a first major surface; and an optical coating disposed over the first major surface. The optical coating comprises: a second major surface; a thickness; and a first gradient portion. A refractive index of the optical coating varies along a thickness of the optical coating. The difference between the maximum refractive index of the first gradient portion and the minimum refractive index of the first gradient portion is 0.05 or greater. The absolute value of the slope of the refractive index of the first gradient portion is 0.1/nm or less everywhere along the thickness of the first gradient portion. The article exhibits a single side photopic average light reflectance of 3% or less, and a maximum hardness from 10 GPa to 30 GPa.