Bot Detector — see what a page is running
A free, open-source Chrome extension that inspects any page and reports the bot-management, verification, and browser-fingerprinting technologies it uses — each with a confidence score. A read-only diagnostic: it analyses the signals already on the page and sends nothing anywhere.
MIT licensed · no account · no telemetry
Detection report
example output · v1.0.0
Know what's on the page first
Modern sites layer CDN rules, bot-management services, and fingerprinting APIs. Whether you're debugging automation you're authorised to run, auditing a site you own, or checking what's tracking you, it helps to know exactly what's deployed.
Bot Detector reads the signals already present on a page — cookies, script URLs, DOM nodes, global objects, JS API calls, and response headers — and maps them to known technology categories, each with a confidence score.
It's read-only and fully local. Nothing is sent to a server, the code is open and auditable, and there's no account to create.
Scope before you build
See which systems a page runs up front, so authorised automation is planned, not guessed at.
Audit a site's posture
Inventory the protection layers on a site you own or test, and confirm they're configured as expected.
See your fingerprint surface
Find out which browser APIs a page reads to identify you, and understand your tracking exposure.
What it recognises
Three categories of page technology, reported by type — never named as targets.
Bot-management systems
16 typesServer- and edge-side systems that classify automated traffic. The extension reports which category of system is present, based on the signals it leaves on the page.
Six signal sources, one report
Detection is fully transparent: each technology is matched from observable page signals, and the more sources agree, the higher the confidence score.
Cookies
Reads cookies set by protection and verification services.
security tokens, session cookies, challenge cookiesScript URLs
Spots the JavaScript files a page loads from known technology categories.
challenge scripts, verification widgets, telemetryDOM elements
Scans for challenge containers and verification iframes in the page.
grecaptcha, h-captcha, turnstile-widgetWindow objects
Inspects global JavaScript variables that frameworks expose.
window.grecaptcha, window._cf_chl_optJS API hooks
Observes Canvas, WebGL and Audio API calls used for fingerprinting.
canvas.toDataURL(), gl.getParameter()Response headers
Parses HTTP response headers that hint at the technology in front of a site.
server, cf-ray, set-cookie, x-* security headersBuilt for developers
Fast, private, and scriptable — the kind of tool you leave pinned to your toolbar.
Real-time detection
Reports the bot-management, verification, and fingerprinting technologies on a page the moment you open it. No setup, no account.
Confidence scoring
Every detection carries a confidence score derived from how many independent signals matched — so you can tell a strong match from a guess.
Fingerprint surface map
Lists which browser APIs a page reads to build a device signature, from Canvas to WebRTC, so you can see your exposure at a glance.
Runs 100% locally
All analysis happens in your browser. No external API calls, no telemetry, no data collection — and no measurable page slowdown.
Configurable
Toggle fingerprint detection, tune cache duration, and turn auto-scanning on or off to fit how you work.
Exportable reports
Copy a structured detection report to your clipboard in one click — handy for tickets, audits, and sharing findings with your team.
Install from source
Five steps, about two minutes. No store listing, no account.
Clone the repo
Download or git clone the open-source repository to your machine.
Open chrome://extensions
Paste chrome://extensions into your address bar.
Enable Developer mode
Flip the Developer mode switch in the top-right corner.
Load unpacked
Click "Load unpacked" and select the extension folder.
Open it on any page
Click the extension icon to see the technologies detected on the current tab.
Add your own detector
A detector is a single JSON file — extend the catalogue without touching code:
{
"detector": {
"id": "my-detector",
"label": "My Technology",
"active": true,
"type": "antibot"
},
"meta": {
"icon": "vendor-default.png",
"color": "#14B8A6"
},
"patterns": {
"cookies": [
{
"match": "my_cookie",
"score": 90
}
],
"urls": [
{
"match": "vendor-script.js",
"score": 85
}
]
}
}drop into detectors/antibot/, detectors/captcha/ or detectors/fingerprint/
"Best and most reliable service for scraping websites"
Who it's for
Developers, security researchers, and privacy-minded engineers.
Development & debugging
See which verification and CDN systems a page runs before you write or debug automation you are authorised to operate. Stop guessing why a request behaves differently from one site to the next.
Security auditing
Inventory the protection layers deployed on a site you own or are testing, and confirm they are configured the way you expect.
Privacy research
Find out how a page tracks you. The extension surfaces every fingerprinting API a site reads to identify your browser.
Technology auditing
Build a quick inventory of the protection and tracking stack a site uses — useful for due diligence, vendor research, and teaching how the modern web defends itself.
Open source, free forever
Bot Detector is MIT-licensed and fully auditable. Star it, open an issue, add a detector, or fork it for your own projects — the catalogue grows with the community.
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