An image forming apparatus includes a reception unit configured to receive image data obtained by reading the document by a first reading unit or a second reading unit, a storage unit configured to store the image data received by the reception unit, a determination unit configured to, while the reception unit is receiving the image data of the document obtained by the first reading unit, determine whether the second side is a blank page from the image data of the document read by the second reading unit, and a control unit configured to, in a case where the determination unit determines that the second side is a blank page, control the reception unit not to reserve a storage area for storing the image data of the document read by the second reading unit in the storage unit.