PrivacyCheck
Browser Privacy & Fingerprinting Checker
Ready
All tests run locally in your browser. No data is sent to our servers.
How to improve your privacy
Use a VPN
A reliable VPN masks your IP address and encrypts your traffic. Look for ones with no-logs policies and modern protocols like WireGuard.
Harden your browser
Use Firefox with privacy extensions like uBlock Origin, CanvasBlocker, and Privacy Badger. Disable WebRTC if you do not need it.
Check regularly
Run this test before and after connecting to your VPN to verify it is working. Bookmark this page for quick access.
Why run a browser privacy check?
Every website you visit sees far more about you than you might expect - your IP address, approximate location, ISP, timezone, language, exact browser and operating system, GPU model, screen dimensions, installed fonts, and dozens of other signals that combine into a highly unique device fingerprint. Research from the Electronic Frontier Foundation has consistently shown that more than 80% of browsers are uniquely identifiable by fingerprint alone, without any cookies or logins.
PrivacyCheck runs twelve independent tests in your browser - no uploads, no accounts, no tracking of results - so you can see exactly what you are leaking and decide what to harden. A VPN fixes some of this, a privacy-focused browser fixes more of it, and browser extensions cover the rest.
How it works
- Click Run All Tests. The page runs 12 tests locally using standard web APIs: WebRTC STUN probes, canvas/WebGL/audio rendering, navigator and screen properties, and a small number of calls to public IP geolocation endpoints.
- Review the score and badges. A score of 80+ means most tests passed. Warnings flag expected-but-identifying data. Fails flag clear leaks you should fix.
- Expand any card for raw values and a plain-English explanation of what the result means.
- Fix the issues and re-test. Enable your VPN, toggle a browser flag, install an extension, then click Run All Tests again to confirm the fix.
Common use cases
VPN verification
Confirm that a newly installed VPN is actually hiding your IP, routing DNS, and blocking WebRTC leaks. Baseline before, compare after.
Hardened browser setup
After locking down Firefox with resistFingerprinting, CanvasBlocker, and uBlock Origin, verify that canvas/WebGL/audio fingerprints are randomized.
Incognito / private browsing audit
See what private mode actually hides - and what it does not. Private mode blocks history and cookies but does not prevent fingerprinting.
Public Wi-Fi check
Before doing anything sensitive on coffee-shop Wi-Fi, confirm your VPN is active and your DNS queries are not leaking to the hotspot operator.
Teaching and training
A concrete, visible demonstration of how much information browsers expose - useful for security awareness, classroom demos, and team onboarding.
What the tests cover
- IP address, ISP, ASN, and approximate geolocation
- DNS query behavior (browser-side signal only - see disclaimer)
- WebRTC leak detection via STUN (stun.l.google.com, stun1, stun2)
- Canvas fingerprint hash (stable across sessions if not randomized)
- WebGL vendor, renderer, and version strings
- Audio fingerprint via AudioContext frequency analysis
- User agent, platform, CPU cores, device memory, vendor
- Screen resolution, color depth, pixel ratio, orientation
- Timezone and UTC offset (used to spot VPN/location mismatches)
- Do Not Track and Global Privacy Control headers
- Cookie and JavaScript enablement
- Network connection type, downlink, round-trip time
Frequently asked questions
Is PrivacyCheck really free and private?+
Yes. PrivacyCheck runs entirely in your browser using client-side JavaScript. Your test results, IP, and fingerprints are never sent to our servers. We use Google Analytics (aggregate page views only) and display ads via Google AdSense to keep the tool free.
What is a WebRTC leak and why does it matter?+
WebRTC is a browser feature used for real-time video and voice calls. It can reveal your real IP address even when you are using a VPN because it bypasses the VPN tunnel at the browser level. Our WebRTC test uses public STUN servers to detect whether your browser is leaking.
What is browser fingerprinting?+
Fingerprinting is a tracking technique that creates a unique ID from your device's characteristics - canvas rendering, WebGL GPU info, audio processing, fonts, screen resolution, and so on. Unlike cookies, it does not store anything on your device, which makes it much harder to block.
Does a high privacy score mean I am anonymous?+
No. A high score on PrivacyCheck means fewer leaks were detected in your browser environment, but real anonymity depends on many factors outside the browser - your network, VPN provider, operating system, extensions, and behavior on other sites. Use the score as a signal, not a guarantee.
What is the difference between a VPN and Tor?+
A VPN routes your traffic through a single provider's servers, hiding your IP from websites but requiring you to trust the VPN operator. Tor routes your traffic through multiple volunteer-run relays, providing much stronger anonymity at the cost of speed. Tor Browser also normalizes fingerprinting values across all users.
Why does enabling Do Not Track make me more unique?+
Paradoxically, fewer than 20% of browsers send the DNT header. That minority status itself becomes a fingerprinting signal. DNT is also voluntary - most trackers ignore it. Global Privacy Control (GPC) has legal weight in California and some jurisdictions.
Can I test my VPN with PrivacyCheck?+
Yes. Run the test once with your VPN disconnected to capture a baseline, then connect your VPN and run it again. Compare IP, DNS, WebRTC, and timezone results. A working VPN will change the IP and DNS servers and prevent WebRTC leaks.
Does PrivacyCheck work on mobile?+
Yes. All tests work in modern mobile browsers (Chrome, Safari, Firefox, Brave). Some fingerprinting vectors behave slightly differently on mobile due to OS restrictions, but the core WebRTC, canvas, IP, and timezone checks all function.
How often should I run the test?+
Run it after any change to your privacy setup - new VPN, new browser, new extensions, OS update. Monthly routine checks are also a good habit, because browser and VPN updates can silently reintroduce leaks.
Can I trust the results?+
The tests run in your browser and show exactly what websites can see about you using standard web APIs. The code is open about what it measures. That said, no single tool is definitive - cross-check critical findings with dnsleaktest.com, browserleaks.com, and ipleak.net.
Disclaimer: PrivacyCheck provides informational diagnostics about your browser environment. It is not legal or security advice. A passing score does not guarantee anonymity or regulatory compliance. For sensitive use cases, consult a qualified security or privacy professional.