Web Development - About Client Capabilities

Web developers are constantly searching for ways to design and implement sites that deliver the best user experience possible. One way to enhance user experience is to customize content based on capabilities that the client browser supports. For example, when a client-side script detects a low-bandwidth modem connection to the server, it may choose to request low-resolution images from the server to minimize bandwidth consumption.

Client capabilities consists of information about the browsing environment, such as screen resolution, screen dimensions, color depth, CPU, or connection speed. Microsoft® Internet Explorer 4.0 exposed client capabilities as properties through the Dynamic HTML (DHTML) Object Model. Internet Explorer 5 enhanced this further to include a means to install browser components on demand. Beginning with Internet Explorer 5, all this information was encapsulated into DHTML behaviors and made available as one of the browser's default behaviors.

By making this information available on the client, pages can be cached, server roundtrips minimized, server resources freed up as content generation shifts back to the client, and overall performance improved.

This article outlines the benefits introduced by a client-side solution and discusses the details involved in obtaining client capabilities information from the client. Realizing that a client-side solution is not suited for every Web site or Web application, a solution for server-side developers is also provided.