Collusion: Who is Tracking You Across the Web?

As we surf the web, we don’t just leave a trace on the servers we visit, but advertisers and advertising networks also track our every moves from page to page with the help of cookies on our own machines. The more they know about us, after all, the more personalized their ads can be. While most of us know this is happening, it’s hard to really understand the extend of how many of these tracking services there are. Thanks to Collusion – a new open source Firefox plugin – you can now get a better idea of who is tracking you across the web.


Once installed, Collusion starts generating an “interactive, real-time visualization of the entities that track your behavior across the web.” The best way to do this is to open up two browser windows. One for Collusion and one for surfing the web. As Collusion detects new cookies, it updates the visualization in real time. Red dots signify services that track you. Gray ones are sites and services that use cookies but don’t use them for tracking purposes.

As Martin Bryant points out on The Next Web, there generally isn’t much you can do about these tracking services and their cookies (besides regularly deleting them from your machine – though that also deletes useful ones that remember your settings and passwords). Thanks to Collusion, though, you can now at least get a better idea of who is tracking you.