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What a Website Can See About You in One Visit

3 min read

You open a page and read it. You don't sign in and you don't type anything. The site still learns more than most people expect, most of it before the page has finished loading. Here's the list, how to see it for yourself, and what actually reduces it.

What a site learns the moment it loads

  1. Your IP address. Every connection needs one. From it a site can usually tell your country and city or region, your internet provider and, on a work or school network, often the organization's name.
  2. Your browser and device. The browser and its version, your operating system, language, screen size and time zone.
  3. Where you came from. The site that sent you, which by default is just its name, not the exact page.
  4. Whether you've been before. Cookies and storage from earlier visits. Third-party cookies (the ones that follow you between sites) depend on your browser: Safari blocks them, Firefox keeps each site's in a separate jar, and Chrome still allows them outside Incognito.
  5. Your browser's fingerprint. Fonts, graphics card, how your device draws text and shapes, audio setup, number of processor cores and dozens of other details. Together they can single out your browser even after you clear your cookies.
  6. What you do on the page. Clicks, scrolling and time spent. Some sites run “session replay” scripts that record mouse movement and typing, which can include text you type into a form and never send.

What it can't see without asking

  • Your exact location from GPS: the browser asks your permission first.
  • Your camera and microphone: the same.
  • Your files: only the ones you choose to upload.
  • Your other tabs and other sites' pages: browsers keep sites apart from each other.

See it for yourself

Two free, well-known test pages show what your browser gives away:

  • Cover Your Tracks from the Electronic Frontier Foundation tests whether your browser blocks trackers and how unique its fingerprint is.
  • BrowserLeaks shows your IP address, fonts, canvas fingerprint and much more, one test at a time.

Run one in your own browser, then run it again from a cloud browser and compare the two results:

Run the same test from a browser that isn’t yours

Free, no sign-up: a 3-minute session in a fresh browser on our server, deleted when it ends.

What actually reduces it

  • A private or incognito window forgets your history and cookies when you close it. It doesn't hide your IP address or your fingerprint from the sites you visit.
  • Tracker blocking (built into Firefox, Safari and Brave, or an extension like uBlock Origin) cuts down tracking between sites. The sites you visit still see your IP address.
  • A VPN hides your IP address from sites: they see the VPN's instead. The VPN company can see which sites you connect to, and your browser's fingerprint is unchanged.
  • Tor Browser hides your IP address and makes you look like every other Tor user. It's slower, and some sites block it or keep asking for CAPTCHAs.
  • A cloud browser such as MyBrowser runs the page on a remote computer and streams you the picture. The site sees that computer's address (for MyBrowser, a data center in the Netherlands) and a fresh browser with no cookies, history or logins of yours. Your own device's details never reach the site, and the remote browser is deleted when the session ends.

The short version

Every site sees your IP address, your device and what you do on its pages. Private windows don't change that. A VPN hides your address, Tor hides it and blends you in, and a cloud browser keeps your device out of it entirely. For a quick look at a site you don't trust, the cloud browser is the simplest of the three.

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