May 20, 2023

Fingerprinting is a technique used by websites to identify and track a user’s device and browsing activity. The term comes from the idea that each device and browser combination is unique, much like a fingerprint, and can be used to create a profile of the user.


The purpose of fingerprinting is to gather information about a user’s browsing behavior, preferences, and habits. This information can then be used for a variety of purposes, including targeted advertising, personalization, and analytics.

For advertisers, fingerprinting can be particularly powerful. By tracking a user’s browsing activity, they can create a detailed profile of their interests and preferences, allowing them to serve more targeted and relevant ads. This not only benefits the advertiser, but can also be beneficial for the user, who may be more likely to see ads for products or services they are interested in.


Fingerprinting works by collecting a range of information about a user’s device and browser. This can include the operating system, browser version, screen resolution, installed fonts, and plugins. By combining this information, it is possible to create a unique identifier for the user’s device and browser combination.

There are a number of different techniques that can be used to collect this information, including JavaScript and Flash. JavaScript can be used to collect information such as the user’s screen resolution, installed fonts, and plugins. Flash, on the other hand, can be used to collect information about the user’s operating system.

Once the fingerprint has been created, it can be used to track the user’s browsing activity across multiple websites. This allows advertisers to build a detailed profile of the user, which can be used to serve targeted advertising.


While fingerprinting can be beneficial for advertisers and users, it has also drawn criticism from privacy advocates. The main concern is that fingerprinting can be used to track a user’s browsing activity without their knowledge or consent.

Unlike cookies, which can be deleted or blocked by the user, fingerprinting is much harder to avoid. This is because it is based on information that is necessary for the browser to function properly, such as the user’s operating system and screen resolution.

In addition, fingerprinting can be used to identify users across different devices and browsers. This means that even if a user deletes their cookies or switches browsers, they may still be tracked using their fingerprint.


There are a number of ways that users can mitigate the effects of fingerprinting. One option is to use privacy-focused browser extensions that block fingerprinting scripts. Another option is to use the Tor browser, which is designed to protect user privacy and prevent fingerprinting.

In addition, some browsers, such as Firefox, have implemented measures to reduce the effectiveness of fingerprinting. For example, Firefox now blocks certain fingerprinting techniques, such as accessing the user’s battery status and screen orientation.