Cookies and fingerprinting: tracking methods clearly explained

March 6, 2018By Bjoern Greif

You have probably heard of cookies and perhaps fingerprinting in connection with online tracking. But do you also know what is behind it and what different variants there are? We introduce the most common techniques that tracker operators use to track you across the web to monitor your browsing behavior. We also explain how you can protect yourself from the different tracking methods.

Tracking can be defined as collecting data points over multiple different web pages and sites, which can be linked to individual users via a unique user identifier. The generation of these identifiers can be stateful, where the browser saves an identifier locally on your device (cookies, supercookies, evercookies), or stateless, where information about your browser and/or network is used to create a unique fingerprint (canvas fingerprinting, audio fingerprinting, JavaScript tracking). In the following we explain these methods in detail.

A cookie is a small text file that is stored on your computer or mobile device for a certain period of time when you visit a website. It contains, for example, log-in data or the current content of your shopping cart. Browser cookies are used to “mark” a visitor of a website in order to recognize them and their settings later on.

Cookies are the most common method of tracking users across multiple websites. Third-party tracking cookies store data about visited websites to log the user’s browsing history over a long period of time. They land on your device via embedded image files (advertising banners or counting pixels). Fortunately, it is pretty easy to delete or block third-party cookies in your browser settings. More information below.

Using all these methods, tracking operators collect massive amounts of data from which they create detailed user profiles to use them for marketing purposes or resell them. They deliberately ignore the users’ desire to browse the Internet unobserved. The more the advertising industry knows about users, the more money they can earn. Highly personal information is stored in the databases of the tracking companies, from which conclusions can be drawn, not only about an individual’s financial situation, interests and shopping plans, but also about his or her sexual orientation, health, political views and religious beliefs.

How to protect yourself

Modern browsers provide basic protection against cookie tracking: In the settings you can specify that cookies are automatically removed when they expire or when you exit the browser. You may also block third party cookies in your browser settings. Setting up a new user profile in your browser is also often helpful to get rid of cookies. With Cliqz you are always on the safe side: No matter what settings you have in your browser, our anti-tracking does intelligent blocking of third-party cookies so that they cannot be used for tracking purposes.

Cliqz’s AI-powered anti-tracking technology implemented in the Cliqz Browserand Ghostery’s anti-tracking tool reliably protects users from being identified by third-party cookies or fingerprinting. It detects when a third-party tracker tries to retrieve unique identifiers or values that could be used as such and replaces the requested data with random values. This ensures that your identity and privacy on the web is always protected. Another advantage of our smart anti-tracking technology is that it protects you from trackers without breaking websites functionalities.