An image forming apparatus includes a generating unit configured to generate an image corresponding to at least part of a plurality of pages included in the print data according to acquisition of the print data, a holding unit configured to hold the image generated by the generating unit into a storage, and an obtaining unit configured to obtain images of all pages to be printed among the pages included in the print data according to the print instruction from the user, wherein the obtaining unit obtains the image of the page of which the image is already generated by the generating unit among the pages to be printed from the storage, and generates, after acceptance of the print instruction, an image of the page of which an image is not generated by the generating unit.