Browser Fingerprint Test

The Navigator object provides detailed information about your browser and operating system. Properties like userAgent, platform, and hardwareConcurrency (CPU cores) are highly identifying. Even the list of installed plugins can make you unique.

Privacy Risk: The webdriver property instantly reveals automation (Selenium, Puppeteer). Properties marked in red are highly unique.

Screen resolution, color depth, and pixel ratio create a unique signature. High-res displays (4K, 5K) or unusual aspect ratios make you stand out. The devicePixelRatio reveals if you're on a Retina display or standard monitor.

Major Privacy Leak: Your timezone (Intl.DateTimeFormat().resolvedOptions().timeZone) reveals your precise location. For example, "America/Los_Angeles" narrows you down to the Pacific coast. Combined with other data, this can pinpoint your city.

Chrome exposes performance.memory which reveals your device's RAM allocation for JavaScript. This is unique to Chrome/Chromium browsers. Higher heap limits suggest more powerful devices.

The navigator.storage.estimate() API reveals how much disk space browsers allocate for IndexedDB, Cache API, and other storage. Large quotas suggest ample disk space, which is another fingerprinting vector.

Browsers support different media codecs based on platform, licensing, and hardware capabilities. Codec support reveals OS type (e.g., H.265 on modern systems), hardware features (VP9 hardware decoding), and even browser vendor decisions. This creates 3-5 bits of entropy in your fingerprint.

Every browser applies default CSS styles to HTML elements. These "user agent stylesheets" vary by browser vendor, version, and platform. By creating a fresh iframe and reading computed styles, we can detect subtle differences in default font families, sizes, margins, and other properties. This provides 2-4 bits of entropy and can distinguish between browsers even with identical user agents.

User-Agent Client Hints (navigator.userAgentData) is Google's replacement for the traditional User-Agent string. It provides detailed OS, architecture, and version information through high-entropy values. This is the future of User-Agent fingerprinting.

The navigator.mediaDevices.enumerateDevices() API reveals all connected audio/video devices. Device counts are highly identifying: desktop users typically have 1-2 cameras and 2-4 microphones (built-in + USB), while mobile users show predictable patterns (1 front camera, 1 back camera, 1 mic).

Privacy Note: Without camera/microphone permissions, browsers only show generic labels like "audioinput 1" to protect privacy. However, device counts are still exposed, providing 3-5 bits of entropy. This reveals hardware setup: gaming rigs (multiple audio devices), professionals (external webcams + studio mics), or mobile users (minimal devices).

Modern browser APIs like Bluetooth, Barcode Detection, and Web Serial reveal browser capabilities and experimental feature flags. The Barcode Detection API is especially rare since it requires Chromium 88+ with experimental features enabled, contributing 4 bits of entropy. The Bluetooth API clearly distinguishes Chrome/Edge from Firefox/Safari (2-3 bits).

Hardware-related APIs like Web USB, Web Serial, and Web NFC are typically only available in Chromium-based browsers and often require HTTPS contexts or origin trials. The Contact Picker API is mobile-only (Android Chrome), instantly revealing device type.

The combination of which APIs are available creates a unique signature, especially for experimental or origin trial features. This reveals not only browser type and version but also whether advanced web platform features have been enabled through flags or enterprise policies.