A heating device includes an endless belt, an opposed rotator, a heater, and a heat transfer portion. The opposed rotator is configured to contact the endless belt to form a nip between the endless belt and the opposed rotator. The heater includes a plurality of resistive heat generators configured to heat the endless belt. The heater is configured to generate a larger amount of heat on a first side of the heater than a second side of the heater in a longitudinal direction of the heater. The first side is opposite to the second side with respect to a center position of a heating span of all the plurality of energized resistive heat generators in the longitudinal direction of the heater. The heat transfer portion is disposed on the first side to release heat from the heating span.