How I built a 1.8-second B2B Lead Scraper & 18-Signal Telemetry Auditor (Zero Headless Chrome)

Most website audit and B2B lead enrichment tools rely on heavy Headless Chrome queues that take 30–45 seconds per domain and cost hundreds of dollars a month in server overhead.

I wanted to build an instant B2B prospecting and technical audit engine for web design, SEO, and PPC agencies that executes in under 2 seconds at the edge for £0 server cost.

Here is the live platform running on Cloudflare Workers:
👉 https://leakradar.leakradar.workers.dev

(If you want to test the locked Pro features—including the 250-domain Bulk CSV Scraper, Contact Vault, and White-Label Client Reports—click *"Unlock Pro"** in the top right and enter the 4-day developer key: VIP-4DAY)*

What It Does in ~1.8 Seconds

When you enter any domain (or hit the JSON API), the Worker fires parallel asynchronous fetch() streams from the nearest Cloudflare PoP across /, /contact, /contact-us, and /about:

1. 18-Signal DOM & HTTP Telemetry Inspection:

   • Ad Pixels: Meta/Facebook Pixel (fbevents.js), TikTok Pixel, LinkedIn Insight Tag, Google Ads Conversion tags.
   • Analytics & Enterprise Stack: GA4, Google Tag Manager, Segment, Tealium, Hotjar, Microsoft Clarity, OneTrust.
   • Conversion Architecture: Live Chat widgets (Intercom, Crisp, Tidio, Drift, Zendesk), CRM/Booking embeds (HubSpot, Calendly, Klaviyo), Lead forms, and JSON-LD application/ld+json schema.
   • Edge & Security: Measures live Time-To-First-Byte (TTFB ms), inspects strict-transport-security (HSTS), and detects CDN edge headers.

2. Cloudflare data-cfemail Hex Decryption + Contact Scraping:

   • Extracts verified corporate @domain emails, tel: phone lines, and social profiles across subpages.
   • Includes a bitwise XOR hex decoder that automatically decrypts Cloudflare's data-cfemail email obfuscation on the fly:

javascript
function decCf(html) {
  let out = [], r = /data-cfemail="([0-9a-fA-F]+)"/g, m;
  while ((m = r.exec(html)) !== null) {
    let s = m[1], k = parseInt(s.substr(0, 2), 16), e = "";
    for (let i = 2; i < s.length; i += 2)
      e += String.fromCharCode(parseInt(s.substr(i, 2), 16) ^ k);
    if (e.includes("@")) out.push(e.toLowerCase());
  }
  return out;
}