Antifingerprinting

Antifingerprinting is the practice of reducing or obfuscating information that could be used to identify a user by browser fingerprinting. Fingerprinting gathers data such as user agent, screen size, time zone, language, fonts, plugins, and canvas or WebGL results to form a probabilistic device profile; antifingerprinting seeks to reduce or standardize these data to limit tracking.

Techniques fall into two broad categories: reducing exposed entropy and adding uniformity or randomness. Reducing entropy includes suppressing or standardizing data points, blocking certain APIs, or spoofing values. Randomization, used in some approaches, makes fingerprints less stable across visits. Implementations include Firefox's privacy.resistFingerprinting, Tor Browser's configuration, and Brave's shielding features, along with network protections like VPNs and the Tor network to hide IP addresses and other network hints.

Limitations exist. Antifingerprinting can break or degrade site functionality that relies on precise data such as locale, fonts, or canvas behavior. It can cause layout issues, CAPTCHA challenges, or slower performance. Trackers continuously adapt, and some signals may still be inferred from broader behavior. Because there is no universal standard, different products balance privacy and usability in various ways, and a combination of measures—such as cookies controls, secure networks, and cautious online practices—is often recommended.

Overall, antifingerprinting is part of the privacy-by-default movement in web browsers. It represents an ongoing arms race between trackers developing more resilient techniques and users seeking to limit digital identifiers, with implementations differing in aggressiveness and compatibility.