Browser fingerprint and TLS policy test

Browser fingerprint and TLS policy

Browser fingerprinting combines what a browser reports about itself and its device: user agent, languages, platform, CPU cores, memory, screen size, colour depth, time zone, GPU and canvas rendering. Individually these are ordinary; together they are often unique enough to recognise a browser without cookies. This view shows the same values a tracker would collect.

The TLS policy test asks what your browser refuses rather than what it offers: a server that only speaks TLS 1.2, one that only accepts a post-quantum key exchange, and one that requires Encrypted Client Hello. A refused handshake is the answer. WebRTC and the Network Information API round out the picture.

What is browser fingerprinting?

Collecting attributes a browser hands out freely, such as the user agent, languages, platform, screen size, time zone, installed fonts, GPU and how it renders a canvas, and combining them into an identifier. Each value is shared by many people; the combination is often unique to one browser, which lets a site recognise you again without a cookie.

What is a canvas fingerprint?

A script draws text and shapes onto an invisible canvas element and hashes the resulting pixels. Small differences in GPU, driver, font rendering and anti-aliasing make the hash differ between machines, so it is one of the strongest single fingerprinting signals. The value shown here is the same one a tracker would compute.

Does WebRTC leak my IP address?

WebRTC gathers the addresses it could use for a call, and a page can read them. Depending on the browser and settings that can include your local network address and, behind some VPNs, the real public address rather than the VPN's. The view shows what WebRTC exposed and whether it matches the address this connection came from.

What does the TLS policy test check?

Three extra servers each accept only one thing: TLS 1.2 without 1.3, a post-quantum key exchange based on ML-KEM, or a connection that uses Encrypted Client Hello. Your browser either completes the handshake or refuses, and the refusal is the answer: it shows which policies your browser or its administrator has set beyond the defaults.

What are Client Hints?

A structured replacement for the details that used to live in the User-Agent string: platform version, CPU architecture, bitness, device model and the full browser version list. A browser sends them only when the server asks, which this page does. What arrived here is what any site that asks can see.

Can I make my browser less unique?

Browsers built for it, such as Tor Browser, make every user look alike, and Firefox's resist-fingerprinting setting rounds off the values that vary most. Blocking single signals in an ordinary browser usually has the opposite effect, since a missing canvas or an unusual screen size is itself rare. The verdict on the overview only uses the signals that indicate a relay, not the fingerprint as a whole.

Related terms: Browser fingerprint, Canvas fingerprint, WebGL renderer, Post-quantum key exchange, Encrypted Client Hello, WebRTC