Browser Feature Usage on the Modern Web
This study provides insights into web complexity and security for web developers and browser engineers, though it is incremental as it builds on existing measurement methodologies.
This work investigates the usage of browser features on the modern web, finding that over 50% of JavaScript features are never used in the Alexa 10k, and that ad and tracking blockers disproportionately block about 10% of features, with over 83% of features executed on less than 1% of the most popular 10,000 websites.
Modern web browsers are incredibly complex, with millions of lines of code and over one thousand JavaScript functions and properties available to website authors. This work investigates how these browser features are used on the modern, open web. We find that JavaScript features differ wildly in popularity, with over 50% of provided features never used in the Alexa 10k. We also look at how popular ad and tracking blockers change the distribution of features used by sites, and identify a set of approximately 10% of features that are disproportionately blocked (prevented from executing by these extensions at least 90% of the time they are used). We additionally find that in the presence of these blockers, over 83% of available features are executed on less than 1% of the most popular 10,000 websites. We additionally measure a variety of aspects of browser feature usage on the web, including how complex sites have become in terms of feature usage, how the length of time a browser feature has been in the browser relates to its usage on the web, and how many security vulnerabilities have been associated with related browser features.