browser fingerprinting and privacy
No single signal, such as timezone, language or screen resolution, identifies a browser on its own, but combining several weak signals at the same time can create a nearly unique impression, known as fingerprinting; this page runs entirely inside your browser and explains the mechanism behind the technique so you understand your own exposure surface, without sending anything to any server.
On its own, timezone only narrows the pool of possibilities down to a broad geographic band; combined with language and resolution, it significantly shrinks the group of browsers that share that exact same combination.
The exact order and length of the language list vary by each user personal setting, making this array a higher-entropy signal than just the first reported language.
Resolution and DPR together narrow the pool of compatible devices to a smaller subset, but on their own they are still shared by millions of other users with the same popular monitor.
User-Agent is a string sent by the browser in HTTP requests and exposed via JavaScript. It usually includes browser, engine, operating system and historical compatibility tokens.
No: every read of timezone, languages, resolution and capabilities happens locally in your browser, and nothing is sent to a server by this tool; the goal is to show which signals exist so you can assess your own exposure, not to collect or combine those signals into any database.
It does not: fingerprinting does not depend on any cookie or stored identifier in the browser, it derives a value from characteristics of the environment itself, such as installed fonts and canvas output, which come back exactly the same as soon as the page reloads, even with every cookie erased.
It barely reduces it: private browsing prevents cookies and history from persisting across sessions, but most signals used in fingerprinting, such as screen resolution, fonts and canvas output, stay identical in private mode, because they depend on the hardware and browser install, not the session state.
The most effective options are using a browser with built-in fingerprinting resistance, such as Firefox dedicated mode, keeping installed extensions and fonts to the minimum necessary, and preferring browsers that already standardize signals such as User-Agent and resolution instead of exposing your machine exact, unique values.
Reading happens locally and does not send User-Agent, timezone or capabilities to analytics.