Tech Stack Detector: website technology lookup for lead lists and competitor monitoring

Find out what any website is built with: CMS, ecommerce platform, analytics, tag managers, marketing automation, ad pixels, payments, live chat, hosting, CDN and the company's email provider. Paste a list of domains (one or 100,000) and get one clean row per site, with versions where the site reveals them. The Actor matches 7,600+ technology fingerprints against each site's HTML, scripts, headers, cookies and public DNS records.

Turn on monitor mode to get alerts when a competitor or prospect adds or drops a tool, such as switching from Mailchimp to Klaviyo or adding a new chat widget.

What you get for each site

Field	Example
domain, finalUrl, status	example-store.com, https://www.example-store.com/, ok
cms, ecommerce	WordPress, Shopify
analytics, tagManagers	Google Analytics, Hotjar, Google Tag Manager
marketingAutomation, advertising, crm	Klaviyo, Meta Pixel, TikTok Pixel, HubSpot
payments, liveChat, reviews	Stripe, PayPal, Intercom, Trustpilot
email (from MX/SPF records)	Google Workspace, Sendgrid
verifiedSaas (from DNS verification records)	Atlassian Cloud, DocuSign, Notion, Zoom
hosting, cdn, webServer, frameworks	Vercel, Cloudflare, Nginx, Next.js
techStack	every technology in one string, ready for a spreadsheet
technologies	name, version, categories, confidence, website and foundIn (the evidence: html, scripts, headers, cookies, meta, or a DNS record such as dns:mx)
byCategory	technologies grouped under all 100+ categories
changes (monitor mode)	{ "added": ["Klaviyo"], "removed": ["Mailchimp"] }

Sample output

{
  "domain": "example-store.com",
  "finalUrl": "https://www.example-store.com/",
  "status": "ok",
  "httpStatus": 200,
  "title": "Example Store: Handmade Ceramics",
  "technologyCount": 14,
  "techStack": "Cloudflare, Google Analytics GA4, Google Tag Manager, Google Workspace, Klaviyo, Meta Pixel, PayPal, Shop Pay, Shopify, Stripe, Trustpilot, ...",
  "cms": "",
  "ecommerce": "Shopify",
  "analytics": "Google Analytics",
  "marketingAutomation": "Klaviyo",
  "advertising": "Meta Pixel",
  "payments": "PayPal, Shop Pay, Stripe",
  "email": "Google Workspace",
  "cdn": "Cloudflare",
  "technologies": [
    { "name": "Shopify", "version": null, "confidence": 100, "categories": ["Ecommerce"], "website": "https://shopify.com", "foundIn": ["cookies", "scripts"] },
    { "name": "Google Workspace", "version": null, "confidence": 100, "categories": ["Webmail", "Email"], "website": "https://workspace.google.com/", "foundIn": ["dns:mx"] }
  ],
  "checkedAt": "2026-10-18T09:00:00.000Z"
}

Use cases

• Lead lists for agencies and SaaS sales. Check a list of prospect domains and keep only the sites running a given platform: every Shopify store that also uses Klaviyo, every WordPress site, every company sending email through HubSpot. Use Only return sites using (with Require all of them for combinations).
• Account research. DNS records show the email provider and the SaaS tools a company has verified its domain with (Atlassian, Notion, Zoom, DocuSign and more), a signal of what it pays for internally.
• Competitor research. See which analytics, ad pixels, A/B testing and personalisation tools competitors pay for. Pair it with our Google Ads Transparency Scraper to see their ads too.
• Stack change alerts. Schedule a weekly monitor run on competitors or key accounts and get only the sites whose stack changed: a new CRM, a replatform, a new payment provider. A change is often a buying signal.
• Market sizing and research. Count how many sites in a list use each CMS, ecommerce platform or analytics tool.
• Due diligence and audits. Inventory the third-party tools on your own sites or a portfolio, with versions.
• AI agents. The structured output (with categories and evidence) is easy for an agent to reason over. Runs are pay-per-site, so agents can call it on demand.

How to use it

1. Paste domains or URLs into Websites, one per line. A bare domain checks its home page; a full URL checks that page.
2. Keep Check DNS records on to also get the email provider, email-sending services and SaaS tools from public DNS.
3. Run it. Export the Overview view as CSV or Excel, or use the One row per technology view for pivot tables.

Monitor mode: get only changes

1. Enter a Monitor name, such as competitors.
2. Turn on Only return sites whose stack changed.
3. Schedule the run weekly. The first run records each site's stack (firstCheck: true). Later runs return only sites with technologies added or removed, listed in changes. A site that can't be read on a given day keeps its last known stack, so an outage never looks like a change.

Use a different monitor name for each list.

Pricing

You pay per site checked: $3.00 per 1,000 sites.

• You pay only for sites the Actor could read. Sites that are unreachable, closed to crawlers by robots.txt, or behind a bot check are returned with an explanation and are free.
• Apify also charges a small fee when a run starts. You can cap the cost of any run with Max total charge.
• With the technology filter or monitor mode, every site checked is billed, including ones that aren't returned, because each one was checked.

Examples: 500 prospect domains cost $1.50. A weekly monitor of 50 competitors costs $0.60 a month.

How it works, and its limits

• Each site is fetched once, directly and politely: the home page (or the URL you give), plus robots.txt. If robots.txt closes the whole site to crawlers, the page isn't fetched and only public DNS is reported.
• Sites that refuse automated visits (HTTP 401/403/429, or a bot check such as a "Just a moment..." page) are reported as blocked, with what headers and DNS reveal. The Actor never tries to get around bot protection.
• The Actor reads the page as served, without running JavaScript. Most technologies leave traces in the HTML, scripts, headers or cookies, but tools that only appear after scripts run (some tag-manager-loaded pixels) can be missed. Run it on a specific URL, such as a product page, to find tools used only there.
• Confidence: most detections are 100%. Weaker signals count 25-75% each and add up when several agree. The default threshold is 50%.

FAQ

Where do the fingerprints come from? From the open-source webappanalyzer project (GPL-3.0), the community-maintained successor to the original Wappalyzer fingerprints, plus our own additions for email and DNS signals. The fingerprint version used is in the run summary.

Does it collect personal data? No. It reports technology names only. It doesn't extract emails, phone numbers, names or social profiles, even when a page shows them, and it keeps no copy of the pages.

How is this different from BuiltWith or Wappalyzer? It is a pay-per-use Apify Actor with no subscription: you pay per site checked, export to any format, schedule runs, and connect it to Make, Zapier, n8n, Google Sheets or your own code through the Apify API. It checks the live site at the time of the run rather than a database of past crawls.

How fast is it? About 1,000 sites in 10 minutes at the default 2 GB memory (measured on 200 well-known sites). Detection is CPU-bound, so a 4 GB run is roughly twice as fast at the same price.

What do the statuses mean? ok (checked and billed); blocked (the site refused automated visits with HTTP 401/403/429 or a bot check, so only headers and DNS are reported); http-error (the site answered with another error page); unreachable (no DNS record, no response within 30 seconds, or a page over 10 MB); robots-disallowed (the site asks all crawlers to stay out). Only ok is billed. On big consumer brands behind enterprise firewalls, expect around 1 in 10 to be blocked; small and mid-size business sites rarely are.

Something missing or wrong? Open an issue on the Issues tab with the domain and the technology. Issues are answered within 24 hours.

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Built and maintained by Rimu Labs. Questions: support@rimulabs.com.