Browser Fingerprinting

Browser Fingerprinting

Have you experienced that spooky feeling that websites know a little too much about you? You might be right. This feeling isn't just paranoia, there's a tool called browser fingerprinting that can create a unique profile based on your device and browser.

This might sound complex, but imagine it like a detective gathering clues. Instead of a hat and magnifying glass, they use info from your browser like what type it is, your screen resolution, and even what fonts you have installed. 

By piecing together these bits and pieces, they can build a digital fingerprint that's almost like a personalized ID for your device. That's what browser fingerprinting is in a nutshell.

What is Browser Fingerprinting?

Browser fingerprinting is a tracking technique used by websites and advertisers to identify and track users without the need for cookies. While cookies can be deleted, making it harder for sites to recognize you on your next visit, browser fingerprinting is more persistent. 

It works by collecting small details about your browser and device settings—such as your screen resolution, operating system, and even the fonts you have installed. When combined, these details can create a "fingerprint" that's unique to your device.

This method doesn't directly harm your computer, but it raises significant privacy concerns because it can track your online activities across different sites without your permission. It's like having someone watch over your shoulder, noting down everything you do, no matter where you go online.

How Does Browser Fingerprinting Work?

Browser fingerprinting works can be likened to piecing together a puzzle. Each piece of information might not tell much on its own, but when combined, they reveal a detailed picture. Here’s a breakdown of the process:

  • As soon as you visit a website, it begins to gather data about your browser and device. This includes both common and less obvious details. For instance, the site might check which browser you are using, your operating system, your device’s screen resolution, and even more technical details like your time zone or the plugins installed.
  • All this gathered information is then compiled into a digital profile. Each piece of data might seem trivial, but collectively, they form a unique or near-unique fingerprint. For example, the combination of your operating system, browser version, and specific settings like font sizes and extensions can distinguish your device from millions of others.
  • This fingerprint is then stored on a server. When you next visit the site or move to another site that uses similar tracking techniques, your current browser details are compared with those previously stored. If they match or closely resemble each other, the website assumes it's the same user.

This method is incredibly effective because it does not rely on traditional cookies, which can be blocked or deleted by privacy-conscious users. Instead, it exploits the inherent way web browsers work—by sharing details with websites to ensure compatibility and functionality. 

As a result, virtually every user inadvertently provides all the information necessary to be tracked just by using their browser normally.

What Are the Different Fingerprinting Techniques?

Fingerprint tracking employs various techniques to collect unique information about users. Each technique explores different aspects of a user’s browser and system to enhance the accuracy of the fingerprint. 

Here are some of the most common browser fingerprinting techniques used:

  1. Canvas Fingerprinting: This technique uses the HTML5 canvas element. Websites can instruct your browser to draw a hidden image. Because each computer’s graphics hardware and software handle this task differently, the image generated can vary slightly. These unique variations in the image are then used to identify and track devices uniquely.
  2. WebGL Fingerprinting: Similar to canvas fingerprinting, WebGL fingerprinting harnesses the power of the WebGL API, which is used for rendering interactive 3D and 2D graphics within any compatible web browser. By examining how your browser renders WebGL graphics, sites can gather information about your GPU and other related hardware characteristics.
  3. AudioContext Fingerprinting: This technique taps into the Web Audio API. It tests how your device processes audio data, capturing discrepancies in audio signal processing that can be traced back to different hardware or software configurations.
  4. Browser Plugin Details: By checking which plugins and extensions you have installed in your browser, websites can create a more comprehensive profile. Each plugin and extension has specific identifiers and versions, adding another layer of uniqueness to your digital fingerprint.
  5. Font Detection: The types and numbers of fonts installed on your device can also serve as an identifier. Since users often install additional fonts, this can vary significantly from one machine to another.
  6. Device and OS Identification: Collecting data about your operating system, device model, and other system settings provides a foundational layer of your digital fingerprint. This includes data points like your operating system version, device configuration, and system language.
  7. Network Information: Gathering network details such as your IP address, DNS configuration, and even your connection speed can help in refining your fingerprint.

These techniques make it clear why this form of tracking is so potent and difficult to evade, there’s no tried and true browser fingerprint test or an anti-browser fingerprinting software that can do the heavy lifting for you. 

Each method extracts bits of information that seem benign but collectively form a tracking mechanism powerful enough to identify individuals across different sessions and websites.


In essence, websites track you with hidden details like browser type and fonts, building a unique fingerprint. Unlike cookies, this is persistent and can't be easily erased. Every browsing session reveals bits of information that paint a detailed picture of your online activity, raising privacy concerns.

Published on:
April 25, 2024
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