What can a website see about you right now?
You haven’t clicked anything, typed anything or accepted any cookie. Here’s what this page, like any other, already knows about you.
Before the page even loads
To send you a page, a website’s server has to know where to send it.
Looking up your address…
The moment it loads
Then the page’s own code can ask your browser a few questions, and your browser answers without asking you. Here are the answers it just gave us.
Reading what your browser shares… (this needs JavaScript, like most websites)
None of these says who you are. But put them together and you’re a lot less like everyone else. That’s called a “fingerprint”.
Why it matters
Each detail on its own is ordinary: plenty of people use an iPhone in Toronto. Combined, they can single out one browser among thousands, and some trackers use that to recognise you again even when you clear your cookies. It’s also how fraud checks spot a stranger logging into your account from a new device.
This page doesn’t keep any of it: the address is looked up on our own server and forgotten, and everything else stays in your browser. Details on the privacy page.
Sources
- MDN Web Docs: Third-party cookies (developer.mozilla.org)
Firefox, Safari, Edge and Brave limit third-party cookies by default in different ways; Chrome only blocks them in Incognito or if you switch it on.
- Global Privacy Control (globalprivacycontrol.org)
A browser setting that tells sites not to sell or share your personal data, required to be honoured under laws such as California’s CCPA. Brave and DuckDuckGo have it on; Firefox lets you turn it on.
- MDN Web Docs: User-Agent header (developer.mozilla.org)
Every request your browser sends names the browser, its version and the operating system.
- DB-IP: IP to City Lite (db-ip.com)
The free database this page uses to match an internet address to a city and a provider, updated monthly.
The questions behind it
- Why does every website ask about cookies?
Another cookie banner? Here's what a cookie really is, why some follow you from site to site, and what happens when you click “Reject all”.
- Is my phone listening to me?
You said “pizza oven” once, and now the ads are everywhere. Here's what researchers found, and where those ads really come from.
More on YouTube
Dan and Liz answer one everyday tech question at a time, most of them in under a minute.