Just like physical fingerprints leave a distinct combination of loops, whorls, and tented arches, the web browser you use to connect to websites leaves its own unique mark. And that mark is called your device fingerprint. It is an identifier of your hardware, software, and browser configuration that can be used to track you across the Internet even after you clear your cookies and switch to another device or browser.

The information used for browser device fingerprint is collected using JavaScript and other tracking methods that are run in the web browser. It is then recorded on the server side and stored in a database. Fingerprints can be matched to other data points, such as IP addresses and cookies, to create a more complete picture of the user.

Browser Device Fingerprint: How It Works and Why It Matters

Despite its effectiveness, device fingerprinting has raised concerns among privacy advocates. While it isn’t illegal, GDPR does require that companies that use fingerprinting ask for consent before gathering personal data from visitors. This can be difficult with a technique such as fingerprinting, as it isn’t necessarily obvious that it is happening.

However, people can limit the information gathered by their browser by installing privacy-enhancing browser extensions and disabling tracking features on their devices. And they can take steps to avoid fingerprinting altogether by using virtual private networks or by switching to a different browser. But, as the technology continues to evolve, it will be more difficult for users to avoid this type of tracking.