The best fingerprinting tools aren't open source they're anti-botting services like CAPTCHA providers & probably ad networks.
This particular service has implementations for several popular fignerprinting techniques but there are so many ways to measure the same thing that even if your fingerprint looks fine on one test a different test of the same measure could detect it as unique. For example a user font fingerprint could be implemented via JS tests, canvas rendering tests or CSS sheets (like in this paper).
The tests that offer the highest degree of hardware variability and uniqueness that I've seen deal with rendering of test and images over canvas.
> how so?
By loading an image that can only be accessed if you're logged in your google / facebook / twitter accounts and checking if the image request returned an error. There's a repo that implements this for >30 different websites, but I can't remember it's name rn. I'll edit this comment later if I remember what it was called
I don't understand how this would work? Wouldn't there have to be some kind of cookie/storage that is accessible to third parties in order to know this? AFAIK this is exactly what angered people about Flash due to their use of cross-domain capable "super cookies".
Click the explanation & protection sections for info on how it works
I think this also assumes you are not using any kind of isolation for your tabs. What I don't understand though, is how it could figure out that I am logged into google even though I have third-party cookies disabled.
What IS the best tool? What other techniques do you know of that it doesn't it implement?
> you being logged in in different services that any website can check
how so?