An image forming system includes an image forming apparatus and a server connectable to the image forming apparatus. The image forming apparatus includes: a model-unique-information transmitting unit that transmits model-unique information of the image forming apparatus to the server; and a function-control mediating unit that controls functions of respective units based on an instruction from the server when an application corresponding to the model-unique information transmitted to the server is executed at the server. The server includes: a model-unique-information receiving unit that receives the model-unique information; an application managing unit that manages and executes the application corresponding to the model-unique information; and an interface unit that instructs the function-control mediating unit to perform control corresponding to the model-unique information, based on an instruction of the control on a function of the image forming apparatus from the application executed by the application managing unit.