In a server 101, a receiver 401 receives a request transmitted from a browser running on a client. A generator 402 generates a response including content according to the request. A transmitter 403 transmits the response to the browser. A determiner 404 determines from the request whether or not an add-on that executes a process in the browser is enabled in the browser. After determining that the add-on is disabled in the browser, content is generated so that a substitute element that executes the process in place of the add-on in the browser is displayed in a content area of the browser. After determining that the add-on is enabled in the browser, content is generated so that the substitute element is not displayed in the content area.