The volume and evolution of web page templates

Web pages contain a combination of unique content and template material, which is present across multiple pages and used primarily for formatting, navigation, and branding. We study the nature, evolution, and prevalence of these templates on the web. As part of this work, we develop new randomized algorithms for template extraction that perform approximately twenty times faster than existing approaches with similar quality. Our results show that 40 - 50% of the content on the web is template content. Over the last eight years, the fraction of template content has doubled, and the growth shows no sign of abating. Text, links, and total HTML bytes within templates are all growing as a fraction of total content at a rate of between 6 and 8% per year. We discuss the deleterious implications of this growth for information retrieval and ranking, classification, and link analysis.