Browser Info

What is browser information detection?

Your web browser sends a wealth of information to every website you visit. This tool reveals exactly what data your browser exposes — including your user agent string, screen resolution, installed plugins, language preferences, cookie settings, and JavaScript capabilities. Understanding this information helps developers build compatible websites and helps privacy-conscious users understand their digital fingerprint.

Every HTTP request includes headers that identify your browser type, version, and operating system. Beyond the basic user agent string, modern browsers expose detailed capabilities through JavaScript APIs — canvas fingerprinting, WebGL renderer information, available fonts, and hardware concurrency (number of CPU cores). Together, these data points can create a nearly unique identifier even without cookies.

What this tool detects

• User agent string — identifies your browser name, version, and operating system.
• Screen resolution, color depth, and device pixel ratio (retina detection).
• Supported features — cookies, JavaScript, WebGL, WebRTC, Service Workers.
• Language and timezone settings configured in your browser.
• Connection type and approximate network speed (if available via Network Information API).

How to use this tool

Simply open this page and all detected information is displayed automatically. No input is required. The tool runs entirely in your browser — no data is sent to any server. You can use this to troubleshoot website compatibility issues, verify your privacy settings, or check what information you are exposing to websites you visit.

Browser fingerprinting explained

Browser fingerprinting combines multiple data points (screen size, fonts, plugins, timezone, language) to create a unique identifier. Research by the Electronic Frontier Foundation found that 83.6% of browsers had a unique fingerprint. Unlike cookies, fingerprints cannot be easily deleted. Privacy-focused browsers like Tor Browser and Brave actively work to reduce fingerprinting by standardizing or randomizing these values.

The user-agent string: what it reveals

The user-agent (UA) string is a short piece of text your browser attaches to every HTTP request. It encodes your browser name and version, rendering engine, and operating system. Websites use this to decide which CSS or JavaScript polyfills to serve. Interestingly, most modern browsers start with Mozilla/5.0 — a legacy artefact from the 1990s browser wars preserved for compatibility. This partial standardisation reduces the UA fingerprinting power, but it still narrows down which browser family and operating system you are using.

What is and is not sent to a server

Everything this tool shows is read inside your browser tab using standard JavaScript APIs (navigator, screen, window, Intl, WebGL). Nothing is uploaded. There is no backend call and no analytics payload transmits your results — you can verify this by watching the Network tab in DevTools. The data displayed is exactly what every website you visit can already read from your browser.

Fingerprint entropy: why small details add up

Each browser signal on its own is not very unique — millions of people share the same screen resolution or language setting. The power of fingerprinting comes from combining many low-entropy signals into one high-entropy composite. If one in ten browsers shares your screen size, one in twenty your timezone, and one in fifty your WebGL renderer string, the joint probability of all three matching is already 1 in 10,000. Real fingerprinting scripts combine dozens of attributes. The EFF Panopticlick project found that over 80 percent of browsers carry a fingerprint unique enough to track users across sites without cookies. Canvas fingerprinting — drawing an invisible image and hashing the pixel output — exploits tiny GPU rendering differences to produce a near-unique hardware signature.

How to reduce your browser fingerprint

There is no single switch that makes you invisible, but these steps lower your identifiability:

• Use a privacy-focused browser. Tor Browser standardises most fingerprint attributes to match all other Tor users. Brave optionally adds noise to canvas and WebGL results.
• Keep your browser updated. A common, current version means more users share your exact UA string, giving you a larger anonymity set.
• Block third-party scripts. Extensions such as uBlock Origin prevent fingerprinting scripts from running on pages you visit.
• Avoid installing unusual fonts or browser extensions. Each uncommon addition increases the entropy of your fingerprint.

Legitimate uses of browser information

Browser detection serves many valid purposes. Responsive design depends on screen width and pixel ratio to serve correctly sized images and layouts. Security teams use browser characteristics as a fraud-detection signal: a login from a headless browser on an unfamiliar OS when your account normally comes from Chrome on macOS is a meaningful anomaly. Customer support teams ask for browser info to reproduce bugs. Accessibility tools read touch support and language settings to adapt their behaviour for different devices.

Frequently asked questions

Is my browser information private?

Most browser information is sent automatically with every web request and is not private. Websites can read your user agent, screen size, language, and many other details without asking permission. You can reduce exposure by using privacy-focused browsers, disabling JavaScript for untrusted sites, or using browser extensions that spoof or block fingerprinting attempts.

Why do websites need to know my browser information?

Developers use browser information to serve compatible content — different CSS for different screen sizes, fallback code for browsers that lack certain features, and appropriate video codecs. Analytics tools use it to understand their audience. Unfortunately, the same data is also used for tracking and targeted advertising without user consent.

Can a website fingerprint me even if I block cookies?

Yes. Browser fingerprinting does not rely on storing anything on your device. It reads attributes already exposed by your browser — screen size, timezone, WebGL renderer, language list — and computes a probabilistic identifier server-side. Clearing cookies or opening a private browsing window has no effect. Only actively randomising or standardising those attributes, as Tor Browser and Brave do, can reduce cross-site tracking.

Does the Do Not Track header actually stop tracking?

No. Do Not Track (DNT) is a voluntary signal indicating a preference against tracking, but most major ad networks ignore it because compliance is not legally required in most countries. The Global Privacy Control (GPC) signal is a newer alternative with legal weight in some jurisdictions such as California under CCPA. Ironically, enabling DNT can make your fingerprint slightly more distinctive because fewer browsers send it.