Impact of HTML structure and CSS on web performance

Abstract

Many statistics about websites and their structures and used resources are available. But those numbers are not clearly placed in web-performance context which can gives a closer notion about best-practices in web development. In this paper, websites from the Moz Top 500 list have been used for the empirical research. The structure of each site was examined. It includes exploring of metadata about DOM and utilization of CSS. This gathered data has been combined with available web-performance statistics. Observed values are visually presented and give a brief image about the current state of the web. With usage of statistical tools relationships in DOM structures have been found. The research also showed that, utilization of served CSS definitions is very low. This fact can directly influence user-experience, because unnecessary data is downloaded. The next part of the research outputs show the impact of website complexity on web-performance.