Privacy Possum is an open-source browser extension for Mozilla Firefox and Google Chrome designed to increase user privacy by reducing and falsifying data gathered by tracking companies. Created by a former developer of the EFF’s Privacy Badger, it is often described as “Privacy Badger on steroids” because it proactively blocks tracking techniques rather than just learning from them.
Key Features and FunctionalityPrivacy Possum works by “monkey wrenching” commercial tracking methods through several mechanisms:
Blocks Tracking Cookies: Prevents trackers from uniquely identifying you across different websites.
Blocks ETag Tracking: Stops trackers from using browser caching to identify users.
Blocks Referrer Headers: Prevents websites from seeing where you came from, protecting your browsing location.
Reduces/Falsifies Fingerprinting: Combats browser fingerprinting by limiting the data shared about your browser’s uniqueness.
Differences from Privacy BadgerWhile Privacy Badger waits to see if a tracker is tracking you before blocking it, Privacy Possum takes a more aggressive approach by immediately blocking many known trackers and reducing the data they collect from the start. Status and Considerations
Obsolete Concerns: Some users have pointed out that modern browsers, particularly Firefox with “Strict” Enhanced Tracking Protection enabled, offer native anti-fingerprinting and privacy protections that may make extensions like Privacy Possum redundant.
Development: It is important to note that, as of early 2026, the extension has not been updated in several years (last updated 2019), which may affect its compatibility with modern browser updates and techniques.
If you are looking for alternatives to enhance your online privacy, I can help you find: Active browser extensions that are currently updated. Browser settings for enhanced tracking protection. VPNs that offer strong privacy protections.