Most of us have gotten used to the little privacy pop-ups that appear when we visit a website. We click “accept,” “reject,” or sometimes just “close” so we can get on with what we came to do. We may even take the time to specify exactly what we will allow or not. Those pop-ups usually talk about cookies. Cookies are so ubiquitous that many people assume they are the main way websites keep tabs on us; however, that is not the case. There is another tracking method that receives much less attention: browser fingerprinting.

Browser fingerprinting is a way for websites to identify your browser by collecting and combining details about it and the device you are using. According to Mozilla’s MDN Web Docs, those details can include things like your screen size, time zone, language settings, browser configuration, and operating system. Each detail may seem harmless on its own, but when enough of them are combined, they can create a distinctive profile, generally called a digital “fingerprint.”

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Think of it this way: one person in a crowd may not stand out because of height alone, shoes alone, or voice alone. Combine enough of these characteristics, however, and it becomes easier to recognize that person again. Browser fingerprinting works in much the same way. A website may not know your name, but it may know that a browser with your exact settings has appeared before.

So why should we care?

Because browser fingerprinting can work even when we think we have protected ourselves. Many of us know we can clear our cookies or use private browsing mode when we are on the Internet. These are still useful steps, but they do not solve everything. That is because trackers can still use browser fingerprinting through scripts that run while a webpage loads, which builds a unique fingerprint tied to you. In other words, privacy is not only about what is stored after you leave a site. It is also about what your browser reveals while you are there.

That is what makes fingerprinting a bit unsettling, as it is often invisible to the average user. You are not usually asked directly, “May we identify your device by its technical traits?” It just happens quietly in the background. For advertisers, analytics firms, and others, that can be valuable, but for many of us, it can mean more tracking and less control.

Privacy regulators are taking notice and considering rules on “storage and access technologies” that are not just limited to cookies but that can also apply to device fingerprinting techniques. This matters in that it signals that browser fingerprinting can no longer be seen as a clever workaround outside the normal privacy conversation. Regulators are increasingly seeing it as part of that conversation.

So, what can you do to lessen your fingerprint?

Here are a few suggestions:

Browser fingerprinting is a reminder that online privacy is about more than clicking “yes” or “no” on a cookie banner. Our devices are constantly sharing small technical clues, and those clues can add up. The Internet may never be completely private, but understanding how browser fingerprinting works gives us a better chance of protecting ourselves. In a world where so much happens behind the screen, knowing what to look for is a good first step toward taking back a little control. To see how well you are protected from tracking and fingerprinting, try the Electronic Frontier Foundation’s “Cover Your Tracks” tool, which offers a useful wake-up call at https://coveryourtracks.eff.org/. It shows how trackers may see your browser and whether your setup stands out from the crowd.