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Cover Your Tracks, explained

Cover Your Tracks, from the EFF, answers a privacy question: how well is your browser protected from trackers? It checks whether you block tracking ads and invisible trackers, and measures how identifying your fingerprint is in bits.

The Electronic Frontier Foundation (EFF), a digital-rights non-profit. Open Cover Your Tracks

What is Cover Your Tracks?

Cover Your Tracks (coveryourtracks.eff.org) is run by the Electronic Frontier Foundation. It began in 2010 as Panopticlick, one of the first public demonstrations that browsers can be identified without cookies, and was renamed in 2020.

It is a privacy test, not a bot test. It shows whether your browser blocks tracking ads and invisible trackers, whether it protects you from fingerprinting, how unique your fingerprint is among browsers tested in the past 45 days, and how many bits of identifying information each attribute carries.

What Cover Your Tracks checks

Tracker blocking

Whether tracking ads and invisible trackers load, which shows whether you use a tracker blocker.

Fingerprint protection

Whether your fingerprint is unique, randomised, or shared with many other browsers.

Fingerprint attributes

User agent, headers, time zone, screen, fonts, canvas, WebGL, audio, hardware concurrency, language, platform and more, each with its own bits of information.

How to read your Cover Your Tracks result

Blocking tracking ads / invisible trackers
"Yes" means a blocker stopped the test trackers. Most people only get this with an extension or a privacy-focused browser.
"Your browser has a unique fingerprint"
No other browser tested in the last 45 days matched yours. Common for any normal browser.
Bits of identifying information
How much your fingerprint narrows you down. Each extra bit halves the number of browsers you could be; 18 bits is roughly one in 260,000.

What real browsers scored

Measured on 20 and 21 September 2026 on one Windows 11 PC (NVIDIA RTX 3070) on a home fibre connection in the Netherlands, with no proxy or VPN. Three browsers: a person's everyday Chrome 153 with an ad blocker, used by hand; the same genuine Chrome 153 driven by Playwright; and Clearcote 153 driven by Playwright with a fingerprint seed.

BrowserCover Your Tracks said
Everyday Chrome 153, by handStrong protection against web tracking · unique among 315,293 browsers tested in 45 days · at least 18.27 bits

We ran this one by hand only, because it is a privacy test rather than an automation test. Even with an ad blocker that stopped the tracking ads and invisible trackers, the fingerprint itself was unique.

Results that show up on normal browsers

  • "Unique fingerprint" on a browser that otherwise blocks trackers well. Blocking trackers and resisting fingerprinting are separate things.

FAQ

Is Cover Your Tracks the same as Panopticlick?

Yes. The EFF launched Panopticlick in 2010 and renamed it Cover Your Tracks in 2020.

What does "bits of identifying information" mean?

A measure of how much your fingerprint narrows down who you are. Each bit halves the pool: 10 bits is about one in a thousand browsers, 20 bits about one in a million.

Why is my fingerprint unique even with an ad blocker?

Ad blockers stop trackers from loading; they don't change what your browser reports about itself. Resisting fingerprinting needs a browser that randomises or standardises those values.

Does Cover Your Tracks test for bots?

No. It measures privacy from trackers. For automation signals, use a test like CreepJS or the Clearcote audit.

Want every check explained?

The Clearcote audit runs 272 coherence checks on whatever browser opens it, with a plain-English explanation and a fix for each one. Free, no account.

Run the audit Other test sites

Related reading

Q&AWhat is browser fingerprinting?Browser fingerprinting identifies a device by combining signals like canvas, WebGL, fonts, and hardware into a stable, often unique hash — without cookies.Test guideAmIUnique, explainedAmIUnique tells you whether your browser fingerprint is unique among the millions it has collected. Almost every browser is, including an ordinary one used by a person, so the useful part is the per-attribute table underneath.ResearchAnatomy of a browser fingerprint: every signal, and why they must agreeA field guide to the signals that make a browser identifiable — grouped by where they come from and how they betray a spoof.Test guideIphey, explainedIphey gives your browser a one-word trust verdict and a score out of 100. It is quick and popular, but the verdict is easy to misread: in our test every browser we tried, including a person's everyday Chrome, was called "Unreliable".Test guidePixelscan, explainedPixelscan tells you whether your browser fingerprint is "consistent" or "inconsistent", with four cards for location, proxy, masking and bots. In our test a person's everyday Chrome got "inconsistent" and "Masking detected", so a red result on its own proves very little.