About JExtScanner

What is JExtScanner?

JExtScanner is a defensive transparency tool inspired by publicly reported research into browser extension detection techniques. It is designed to help you explore and understand these behaviors firsthand — not to track, collect, or exploit user data.

What does JExtScanner mean?

JExtScanner stands for JavaScript Extension Scanner, reflecting its focus on detecting browser extensions and analyzing web-based exposure techniques.

What This Tool Demonstrates

Modern websites can use standard browser features to infer information about your environment, including installed browser extensions, browser and version details, device and screen characteristics, and signals used in browser fingerprinting.

JExtScanner visualizes these techniques so you can see what may be observable from your browser.

How Extension Detection Works

Browser extensions may expose certain files (called web-accessible resources) to function properly. These files are reachable at predictable URLs like chrome-extension://EXTENSION_ID/resource.png.

Websites can attempt to load these resources: if a resource loads, the extension may be installed; if it fails, the extension is likely not present. By testing multiple known resources, websites can infer parts of your extension set.

Why It Matters

Your browser configuration can act as a unique signal:

  • Fingerprinting: Your combination of extensions can make your browser more identifiable
  • Profiling: Extensions may reveal usage patterns (e.g., developer tools, privacy tools)
  • Targeting: Detected signals may be used for personalization or analytics

JExtScanner helps make these otherwise invisible signals visible.

Privacy First by Design

  • All scans run locally in your browser
  • No extension data is transmitted or stored
  • No tracking, analytics, or logging

Desktop Browser Required

Important note: The core scanning functionality (chrome-extension:// URL probing) is a Chromium desktop-only feature. It won't work on any mobile browser (Chrome mobile, Safari, Firefox mobile). The site is fully viewable and informative on mobile, but the actual scan must be run on a desktop.

Built By

Antibody Cyber Technology LLC — Built for privacy, transparency, and user control.