Demystifying content-blockers: A large scale study of actual performance gains

Abstract: With the evolution of the online advertisement and tracking ecosystem, content-filtering has become the reference tool for improving the security, privacy and browsing experience when surfing the Internet. It is also commonly believed that using content-blockers to stop unsolicited content decreases the time needed for loading websites. In this work, we perform a large scale study with the 100K most popular websites on the actual performance improvements of using content-blockers. We focus our study in the two most relevant metrics for user experience; bandwidth and latency. Our results show that using such tools results in small improvements in terms of bandwidth usage but, contrary to popular belief, it has a negligible impact in terms of loading time. We also find that, in the case of small and fast loading websites, the use of content-blockers can even result in increased browsing latency.