A method for differential rendering a portal page that includes a plurality of page elements (10, 12, 14) and refreshing the portal page. The method includes providing a complete portal page (20, 22). A request for the portal page is then sent and / or received (28). The request can represent user events. In a next step, page elements (10, 12, 14) of the portal page to be updated are identified (30, 31) on the basis of the user events. A page delta is then calculated (32), wherein each page element (10, 12, 14) is associated with a refresh policy depending on the semantics of the respective page element (10, 12, 14). The page delta can include the markup elements of the page elements to be updated. Next the page delta is transferred (34) to the existing portal page and merged (40) with the existing portal page.