A fingerprint is the pattern that emerges from all your browser settings together. This is what websites can make of it.
A website has to store cookies, and you can throw them away. A fingerprint works without storage: a site measures dozens of properties of your browser and turns them into a single number. Your language settings, your time zone, your screen size, your fonts, your graphics card. Each detail says little on its own, but the combination often occurs in only a handful of people worldwide.
The best-known tricks are canvas and WebGL. The site has your browser draw a piece of text or a 3D shape off-screen and looks at the result pixel by pixel. Differences in graphics card, drivers and fonts make the outcome on your device slightly different from the one on your neighbor's, and that difference stays the same long enough to recognize you later.
This page computes the fingerprint with FingerprintJS, inside your own browser. WhoIP keeps a hash of it, along with your IP address and your user agent, to see how many unique visitors the site has. There is no ad network attached to it and no third-party analytics scripts run here.
Barely. An incognito window wipes your cookies and your history, but your screen, your graphics card and your fonts stay the same. So the fingerprint hardly changes.
Turning it off completely is impossible, because websites need some of those properties to work. Tor Browser and the strict modes of Firefox and Brave do make you a lot less unique by smoothing out the sharp edges.
It does. A browser update, a new driver for your graphics card or one extra font can shift the outcome. Trackers count on that and work with probabilities instead of a hard match.
In the EU, reading out your device falls under the same rule as cookies: it is only allowed with your consent, unless it is strictly needed to deliver the service. In practice it happens without, and regulators have started paying attention.
Your visit is stored with your IP address, your user agent and the hash of your fingerprint, so the visitor statistics add up. We sell nothing on and share nothing with third parties.