A method, system, and medium are provided that relate to dynamically instrumenting a website. In general, an exemplary aspect of the invention includes storing configuration information in a datastore. A unique identifier, which corresponds to configuration information, is inserted within code of one or more web pages that relate to the website. When content is requested from the website, such as by a browser, the unique identifier can be used to retrieve corresponding configuration information. Using corresponding configuration information, instrumenting code may be generated and communicated, thereby instrumenting the website.