A runtime capability check determines functionality supported by a client application (e.g. a browser) on a computing device. During the runtime capability check, the client application (e.g. the browser) attempts to execute different function tests to determine its capabilities. The result information from the function tests are stored. The stored result information is used by the client application during subsequent connections with the server (e.g. the cookie is passed from the mobile computing device to the server). Based on the supported functionality as determined by the stored result information, the rendering code is adapted for, generated and delivered to the computing device by the server. For example, when the client application supports the tested functionality then the server renders the content using full feature rendering. When the client application does not support all of the tested functionality then the server renders the content using limited feature rendering.