Your Browser Has a Fingerprint, and There’s Nothing to Delete

How browser fingerprinting can link your visits, even before you log in.


Open a website and do nothing else. Don’t log in and don’t type anything yet.

The website may already be able to learn quite a bit about the device and browser you’re using. That includes things like your browser version, operating system, language, time zone, screen dimensions, available fonts, graphics capabilities and other details exposed as part of ordinary web browsing.

While none of those details can identify you on its own, put enough of them together and the result can be something strongly distinctive.

That’s the basic idea behind browser fingerprinting.

But why should you care? Because a site that recognizes your browser can link your visits over time, and a tracker that appears on many sites can follow the same browser from one to the next, with no login and no cookie involved. A fingerprint has no name in it, but the moment that browser logs into an account, the history can be connected to you. And because a fingerprint isn’t saved anywhere on your device, there is nothing for you to delete.

Back in 2010, the Electronic Frontier Foundation (EFF) put up a test page that showed visitors what their browser was revealing to the websites they visited. About 470,000 people took part, and for roughly 84% of them, the combination of information their browsers exposed produced a fingerprint that was unique within the study.

Of course, browsers have changed a lot since 2010. Flash and Java, which gave away part of that information, are gone, and some browsers now limit what they share. But fingerprinting adapted too. Newer signals have partly taken their place, like the way your device renders an image.

Where a fingerprint comes from

Websites need some of this information to work. A page has to know your screen size to display properly, and your language to show the right text, so the browser hands those answers over automatically whenever a page loads.

You may share your first name with thousands of people, or even millions, but add your birth month and your street and that group gets a lot smaller.

Some of the signals come from your hardware. In canvas fingerprinting, a script asks your browser to draw a hidden image, with text and shapes, then reads back the pixels.

Differences in graphics hardware, drivers and fonts can produce slightly different results, and those differences are turned into a short code. That code becomes one more piece of the fingerprint that helps recognize your browser later.

In 2014, researchers at KU Leuven and Princeton checked popular websites for canvas fingerprinting and found it on more than one in twenty. Most of those scripts came from a single sharing-button company called AddThis, which stopped using the technique within days of the paper coming out. Two years later, a re-run found it back in use, now spread across many smaller trackers, and the authors link that to a lack of ongoing monitoring.

Who uses it, and why it’s hard to stop

Fingerprinting does have legitimate uses too. Banks and online shops use it to spot fraud and bots, for example when a login comes from a device nobody has seen before, and security researchers count that among its proper uses.

The other main use is advertising and tracking. As more browsers restrict third-party cookies, some companies have looked at fingerprinting as a replacement, and in 2025 Google changed its advertising policies to allow it. The UK’s data protection regulator, the Information Commissioner’s Office (ICO), called the move irresponsible.

Fingerprints can’t be cleared the way cookies can. A cookie is a tag a website leaves on your device, and if you delete it, the website no longer has it. A fingerprint is never stored there at all, since it gets worked out again from the same signals on every visit. The ICO points out that consent banners and “clear site data” options mostly deal with cookies and local storage, while fingerprinting is harder for browsers to block, which reduces people’s choice and control over how their data is collected. In the UK, businesses have to give people fair choices, and get consent where needed, before using it.

How to be harder to track

Some of the browsers try to deal with this, and they don’t all do it the same way. Tor Browser tries to make everyone look the same. It puts window sizes into a few standard groups, reports a standard operating system name, and limits which fonts and languages sites can see. The Tor Project admits that making all users identical is practically impossible, but each step shrinks the number of groups a user can fall into.

Firefox blocks the scripts themselves. With Enhanced Tracking Protection set to Strict, it stops scripts from a list of known fingerprinters and limits what sites can read about canvas images, installed fonts and the number of processor cores. Safari 26 added a protection, on by default for all browsing, that limits what known fingerprinting scripts can read, such as canvas rendering and precise screen details.

Changing settings yourself can backfire. If you edit how your browser describes itself, or install an extension that scrambles your canvas results, you can end up with a combination almost nobody else has, and that makes you easier to recognize. A browser that claims to run Linux while reporting Windows details is rarer than either one, which is why the EFF advises against changing settings one by one. The EFF also calls the existing defenses imperfect, and notes that blockers like Privacy Badger only cover some fingerprinting domains.

You can check how unique your own browser looks with the EFF’s Cover Your Tracks test (https://coveryourtracks.eff.org), which also shows whether your tracker blockers are working. It logs results anonymously to compare against other visitors. If you use Firefox, you can also check that Enhanced Tracking Protection is set to Strict.

Keeping your digital self to yourself

But your browser’s fingerprint is only one of the traces you leave online. Every app and account you use keeps its own record of you, with your messages in one place, your payments in another and your sign-ins in a third, and together they make up a digital version of you that other people can piece together. Protecting that digital self means a lot more than choosing the right browser.

SourceLess is about giving you more control over that digital self, starting from privacy and independence. Its platforms are meant to work together as one connected ecosystem, with one identity across them, so your digital life isn’t fragmented across separate accounts.

Str4tus is the SourceLess browser, though not one meant to replace the browser you already use every day. It works as a gateway into the ecosystem, one window where you can see and reach all the SourceLess platforms, among them STR Talk for private messaging, Ccoin Finance for payments and banking, STR Domains for your name and ARES AI for AI assistance. Each of them can still be opened on its own. By default, Str4tus has zero tracking fingerprints. It also encrypts every connection with GodCypher, so what you send and receive can’t be read along the way. ZK13 routing then passes that traffic through the SourceLess mesh, a network of connected points, on its way to the service.

Str4tus is still Alpha v0.1 for macOS and Windows, so some features are incomplete while testing continues.

If you want to keep your digital self to yourself and see how the platforms work together, you can try the Alpha at https://str4tus.sourceless.net