Abstract: Devices, systems, and methods are provided for a tote stacker machine. A tote stacker system may include a first conveyor belt, a sensor to determine an orientation of a first tote on the first conveyor belt, an end effector that moves in a lateral direction between a first position aligned with the first conveyor belt and a second position, and an elevator that is aligned with the second position and that includes a first track and a second track. The elevator may receive the first tote from the end effector and may down stack the first tote with a second tote. The tote stacker system may include a second conveyor belt at least partially positioned between the first track and the second track of the elevator, and the second conveyor may move the first tote and second tote away from the elevator.