The DOM Environment supports two types of profiles - one stictly for models (Model profile) and one that is either directly inserted into HTML or exists as a stand-alone file. Profiles that operate in the Classic Environment may be supported by the browser to the extent that they conform to the DOM Envirnoment. The HTML profile is a proper superset of the Model profile - every node in the Model profile is in the HTML profile and the HTML profile contains nodes that are not in the Model profile. Each profile allows a number of extensions to support different capabilities. If a browser supports an extension for the Model profile, it shall support the same extension for the HTML profile.

The HTML profile provides the interaction with the user environment. These include capabilities for Viewpoints, Sensors, and Navigation. Interaction between the X3D scene and the HTML is provided by code external to the X3D Scene (typically JavaScript in the HTML page). This code is not part of the X3D scene and cannot be included in an a stand-alone HTML profile file.