CCDBR Ally EFF Releases Browser Tracking Detection Tool
Posted on May 24, 2025
The Electronic Frontier Foundation (EFF), an ally of CCDBR through the Electronic Frontier Alliance (EFA), has released a free tool for detecting your browser’s susceptibility to various user tracking techniques. Known as Cover Your Tracks, the EFF’s latest web-based application subjects your browser to a battery of browser tacking tests, and then produces a report of how easily you can be uniquely identified by your browser.
Cover Your Tracks focuses on determining the extent of a user’s browser “fingerprinting”, the ability of websites to uniquely distinguish an individual web browser as it navigates across the web. While discovering the real-world identity associated with a browser would constitute fingerprinting, fingerprinting does not require such identification, and thus typically does not go to such lengths. Its aim is solely to single out a browser regardless of who is at the keyboard. For ad sellers like Google, this is sufficient—they don’t need to know your name to show you tailored ads based on where they’ve watched your unique browser go on the web.
Cover Your Tracks’ test suite consists of more than a dozen known browser fingerprinting methods commonly used by web ad vendors, information brokers, and the like. In the reports it produces, Cover Your Tracks explains how each tested technique works, and what it learned from applying that technique on you. In essence, Cover Your Tracks holds up a mirror to your browser so you can see what it looks like to web trackers.
While some techniques can fingerprint your browser by themselves, others can be used to gain piecemeal information about your browser and, when aggregated, yield a unique combination. To evaluate how effective each technique is, Cover Your Tracks anonymously compares your data against that of prior users of the tool to see how common that data point is in their dataset for that test. For example, when testing browser timezone configurations, America/Chicago makes up 1 out of 17.8 browsers represented in their database. Smaller proportions (e.g. 1 in 17.8 is smaller than 1 in 2) mean your browser is less common, and thus easier to pick out on the Web. After accounting for the results of all its tests, the tool indicates whether your browser is unique within the EFF test dataset.
Evading these web trackers, which are most commonly the instruments of web ad vendors, is vital to privacy online, generally. Moderately sophisticated governments are capable of utilizing the same techniques to spy on your digital First Amendment activity, and modestly-funded ones can (and do) purchase this data directly from web ad businesses. Thus, defeating ad tracking is not merely an end in itself, but a means to shrug off the first line of attack by state surveillance.
The level of detail in the report, the transparent methodology, and the simple explanation of each test module provides results that are useful for tech professionals and average Internet users alike. This makes EFF’s latest privacy offering an essential and accessible tool for anyone interested in Internet privacy—to ensure privacy while browsing the Web, one must know what undermines that privacy, and how to address it.
You can try Cover Your Tracks at coveryourtracks.eff.org.
