An image output system includes a terminal, a server, and a printing device that are communicable with each other via a network. The server includes: a storage device; and a CPU that executes a program for the server to function as a data generating portion configured to generate raster image data by executing a RIP process on the basis of print data received from the terminal and as a data transmitting portion configured to transmit data for outputting an image, to a destination that outputs the image. The data transmitting portion transmits, to the destination, the print data received from the terminal or the raster image data generated by the data generating portion, according to a kind of the destination.