There is provided an image forming apparatus configured to process print data of a plurality of pages includes a plurality of interpreters configured to generate intermediate data of the plurality of pages by interpreting the print data, a control unit configured to specify different pages for different interpreters, and, for each specified page, cause a corresponding interpreter to generate the intermediate data of the specified page or specified pages, and a generation unit configured to generate a raster image of the page based on the generated intermediate data, wherein, based on interpretation of the print data of an invalid page, any one interpreter of the plurality of interpreters generates the intermediate data of a page subsequent to the invalid page without requiring the page to be specified by the control unit.