Via Life Hacker
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How anonymous are you when browsing online? If you're not sure, head
to StayInvisible, where you'll get an immediate online privacy test
revealing what identifiable information is being collected in your
browser.
The site displays the location (via IP address) and
language collected, possible tracking cookies, and other browser
features that could create a unique fingerprint of your browser and session.
If you'd prefer your browsing to be private and anonymous, we have lots of guides for that. Although StayInvisible no longer has the list of proxy tools we mentioned previously, the site is also still useful if you want to test your proxy or VPN server's effectiveness. (Could've come in handy too for a certain CIA director and his biographer.)
StayInvisible