Website Tech Stack Detector — Signals & Alerts

See exactly what any company runs its website on — and get pinged the day they switch.

Feed this Actor a list of domains and it tells you the technology behind each one: CMS, ecommerce platform, analytics, chat widget, payment provider, JS framework, CDN, marketing automation and more — ~110 technologies across 20 categories. Turn on diff mode, schedule it daily, and it only reports a site when it adopts or drops a tool. That change is the B2B buying signal.

BuiltWith and Wappalyzer sell "companies that use technology X" lists for $295–995/month. This does the same detection on your own target list, on your schedule, for cents — with data you own.

Why it's different

Most Apify tech scrapers dump raw HTML. This one gives you a clean, categorized stack per site plus change tracking — the difference between "here's a page" and "here's a qualified lead who just installed Intercom."

• Official page markup only. It reads the public homepage HTML and response headers — the same signals Wappalyzer, BuiltWith and your browser's dev tools use. No proxies, no logins, no ToS-risky scraping.
• Diff mode = sales signals. newTech / removedTech per site. "Target account started using Shopify Plus" or "dropped Zendesk for Intercom" → a reason to reach out today.
• Evidence included. Every detection ships with the exact marker that triggered it, so you can trust (and audit) the result.

Use cases

• B2B sales & lead gen: filter your prospect list to "uses Stripe" / "runs on Shopify" / "just added a chat widget," then sell the matching integration or service.
• Competitive intelligence: watch competitors' stacks and get alerted when they change vendors.
• Agencies: qualify inbound by platform (WordPress vs Webflow vs custom) before the first call.
• Investors/analysts: tech adoption as an alt-data signal across a portfolio of companies.
• Partnerships: find every site already running a tool that complements yours.

Detected categories

CMS · Ecommerce · Analytics · Tag managers · Advertising / pixels · Chat & support · Marketing automation · CRM · Payments · JS frameworks · CDN & hosting · Web servers · A/B testing · Error monitoring · Consent & privacy (CMP) · CDP · Email & forms · Video · Fonts & UI · Search

Input

{
    "domains": ["stripe.com", "notion.so", "shopify.com"],
    "newTechOnly": false,
    "trackChanges": true,
    "computeSignals": true
}

Parameter	Type	Description
domains	Array (required)	Domains or URLs to analyze. stripe.com, https://notion.so, etc. One homepage fetched per entry.
categories	Array	Restrict detection to specific categories. Empty = detect everything.
newTechOnly	Boolean	Diff mode: only output sites whose stack changed since the last run. First run primes the memory.
trackChanges	Boolean	Remember each site's stack between runs and fill newTech / removedTech. Default true.
onlyDetected	Boolean	Skip rows for sites that couldn't be fetched (timeouts, blocks).
computeSignals	Boolean	Append one run-summary item: totals by category, top technologies, share using chat / payments / analytics.
maxConcurrency	Integer	Sites fetched in parallel (1–20, default 5).

Output

One record per site:

{
    "type": "site",
    "domain": "stripe.com",
    "url": "https://stripe.com/",
    "statusCode": 200,
    "title": "Stripe | Financial Infrastructure...",
    "server": "nginx",
    "technologies": [
        { "name": "Stripe", "category": "Payments", "confidence": "high", "evidence": "html: js.stripe.com/v3/" },
        { "name": "Cloudflare", "category": "CDN & hosting", "confidence": "high", "evidence": "header cf-ray: 80a1..." }
    ],
    "techByCategory": { "Payments": ["Stripe"], "CDN & hosting": ["Cloudflare"] },
    "techCount": 2,
    "newTech": ["Stripe"],
    "removedTech": [],
    "isNew": false,
    "scrapedAt": "2026-07-07T12:00:00.000Z"
}

Plus one run_signals summary per run (unless disabled).

Scheduling for alerts

Set newTechOnly: true, schedule the Actor daily, and connect a Slack / email / webhook integration. You'll only hear about a domain when its stack actually changes — a lightweight, always-on competitor-and-prospect radar. Runs cost cents because there are no proxies and only the homepage is fetched.

Notes & limits

• Detection is based on the homepage only. Tools loaded exclusively on deeper pages (e.g. a checkout-only payment SDK) may not appear until v1.1 adds optional sub-page crawling.
• Presence, not version: it reports that a technology is used, not which version.
• Sites that hard-block bots or render everything client-side after load may expose fewer markers.

FAQ

Is this allowed? It only reads public homepage markup and HTTP headers — the same data your browser receives. No authentication, no proxies, no private data.

How accurate is it? Signatures are the documented, stable fingerprints used across the industry. Each hit includes the evidence so you can verify it yourself. High-confidence markers are vendor-specific; medium-confidence ones are heuristic.

Part of a suite. Pair it with our ATS Jobs Scraper (hiring signals) and Mentions Monitor (conversation signals) for a full B2B signal stack: who's hiring, what they run, and where they're talked about.