The dataset contains and processes results of a large-scale survey of 708 websites, made in December 2019, in order to measure various features related to their size and structure: DOM tree size, maximum degree, depth, diversity of element types and CSS classes, among others. The goal of this research is to serve as a reference point for studies that include an empirical evaluation on samples of web pages. See the Readme.md file inside the archive for more details about its contents.