An image processing apparatus includes a processor and a memory including instructions. The instructions, when executed by a processor, cause the processor to perform operations including: receiving a print job data in a PDL format from an external apparatus; determining whether a Generator of the print job data satisfies a guarantee condition guaranteeing compatibility with the image processing apparatus; upon determining that the generator of the print job data does not satisfy the guarantee condition, executing a preflight processing of checking a syntax of the print job data and then developing the print job data subjected to the preflight processing into an image data; and upon determining that the generator of the print job data satisfies the guarantee condition, skipping the preflight processing and then developing the print job data not subjected to the preflight processing into an image data.