Methods and computer program products are disclosed for providing QoS for Web applications via an internet service application programming interface "ISAPI") filter running on an internet information server, wherein the ISAPI filter uses a traffic control application programming interface to manage bandwidth for individual HTTP requests. Responses to HTTP requests can be prioritized based on policies defined by the Web application developer, wherein policy decisions may be made based on many different parameters, such as, for example, the IP address of the Web browser making the request, the type of browser being used, HTTP "cookies," the uniform resource locator being requested, an authenticated user ID, or any other information that is exposed from the internet information server through server variables. The present invention accomplishes this with no modifications to the internet information server, and .cndot.with very minimal changes to the Web application.