An image forming apparatus includes a conveyor, a sensor, and control circuitry. The conveyor is configured to convey a sheet. The sensor is configured to detect the sheet conveyed by the conveyor. The control circuitry is configured to cause the conveyor to eject the sheet without stopping conveyance of the sheet and prohibit recovery printing when a size of the sheet determined based on detection of the sheet by the sensor is different from a setting size in a first operation mode. The control circuitry is configured to cause the conveyor to stop conveyance of the sheet and allow recovery printing when the size of the sheet is different from the setting size in a second operation mode in which a number of times of printing is larger than a number of times of printing in the first operation mode.