Tech Stack Detector: find the technologies behind any website

Paste a list of domains and get back each website's CMS, ecommerce platform, analytics, advertising pixels, frameworks, CDN, hosting, payment providers, marketing tools and more, plus something most tech lookups can't show you: the SaaS tools the company uses internally (HubSpot, Salesforce, Atlassian, Microsoft 365, Zoom, Figma, OpenAI...), revealed by public DNS verification records.

• 🔍 7,600+ technology fingerprints, refreshed from the open-source database on every run
• 🏢 Company tools from DNS: internal software you can't see on the website itself
• 📄 Bulk input: domains, URLs or email addresses, thousands per run
• 💸 $4 per 1,000 websites. Unreachable, blocked and error pages are free
• 🔑 No API key, no subscription, no browser extension

What can you use it for?

You are...	Use it to...
Sales / SDR team	Build lists of companies that use (or don't use) a tool you integrate with or replace, e.g. "Shopify stores using Klaviyo" or "companies on HubSpot".
Agency	Find WordPress, Wix or Squarespace sites to pitch redesigns, migrations or maintenance plans.
SaaS founder	Size your market, and track competitor adoption across thousands of sites.
Investor / analyst	Map technology adoption in a sector or portfolio.
Security team	Inventory your own domains and spot outdated software versions (CPE identifiers included).
AI agent builder	Give your agent a fast, cheap "what is this site built with?" tool via API or MCP.

What data do you get?

For every website:

• Quick answers: cms, ecommercePlatform, pageBuilder, webServer, cdn, paas
• Stacks by purpose: analytics, tagManagers, advertising, marketingAutomation, crm, liveChat, paymentProcessors, buyNowPayLater, abTesting, cookieConsent, reviews, emailTools, aiTools, shopifyApps, wordpressPlugins, jsFrameworks, webFrameworks, programmingLanguages, security
• Full technology list with category, version (when exposed), confidence, website, icon, pricing model, CPE and the evidence behind each detection
• Company tools from DNS (companyToolsFromDns): e.g. Atlassian Cloud, Microsoft 365, Google Workspace, HubSpot, Salesforce, Zoom, Figma, Miro, DocuSign, OpenAI, Anthropic, Cursor, Jamf, HackerOne
• techNames and companyToolNames as comma-separated text, so CSV / Excel / Google Sheets exports stay readable

Sample output (trimmed)

{
  "domain": "basecamp.com",
  "url": "https://basecamp.com/",
  "cdn": "Cloudflare",
  "jsFrameworks": ["Stimulus"],
  "marketingAutomation": ["MailChimp"],
  "techNames": "Bootstrap, Stimulus, Cloudflare, MailChimp, Priority Hints, Open Graph",
  "companyToolNames": "Atlassian Cloud, Microsoft 365, Cloudflare DNS, Zoom",
  "technologies": [
    {
      "name": "Cloudflare",
      "categories": ["CDN"],
      "confidence": 100,
      "version": null,
      "website": "https://www.cloudflare.com",
      "evidence": ["header:server", "header:cf-ray", "dns:NS"]
    }
  ]
}

How to use it

1. Paste your domains into Websites (one per line; https://, www. and paths are fine, and emails are converted to their domain).
2. Click Start.
3. Download the results as CSV, Excel, JSON or HTML, or send them to Google Sheets, Make, Zapier, n8n, Clay or your CRM via the Apify integrations.

Run it from code

curl -X POST "https://api.apify.com/v2/acts/plainsight~tech-stack-detector/run-sync-get-dataset-items?token=YOUR_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"domains": ["stripe.com", "notion.so", "allbirds.com"]}'

from apify_client import ApifyClient

client = ApifyClient("YOUR_API_TOKEN")
run = client.actor("plainsight/tech-stack-detector").call(run_input={"domains": ["stripe.com", "notion.so"]})
for site in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(site["domain"], site["cms"], site["techNames"])

AI agents: this Actor works as a tool through the Apify MCP server (Claude, Cursor, VS Code and other MCP clients), and agents can pay per call without an Apify account via x402.

Pricing

You pay $0.004 per website successfully analysed ($4 per 1,000). You are not charged for domains that don't resolve, time out, return an error page, or block automated visitors. Those rows are still in your results so you can see what happened.

Apify's free plan includes monthly platform credit, enough to analyse roughly a thousand websites a month for free.

Try it free: start a run with an empty input and it analyses 3 sample websites at no charge, so you can see the exact output format first.

How does detection work?

For each website the Actor loads the homepage (following redirects), robots.txt and the domain's DNS records (TXT, MX, NS, SOA, CNAME), then matches them against the webappanalyzer fingerprint database, the actively maintained open-source continuation of the Wappalyzer fingerprints (GPL-3.0). It checks HTML, script URLs, inline scripts, HTTP headers, cookies, meta tags, DOM selectors, robots.txt and DNS records, and resolves implied technologies (e.g. WooCommerce → WordPress → PHP).

The database is downloaded fresh at the start of every run, so newly added technologies are picked up automatically.

Limitations (honest ones): detection is based on what a server sends. The page's JavaScript isn't executed in a browser, so technologies that can only be seen at runtime (a small share of fingerprints) may be missed, and single-page apps that render everything client-side can show fewer results. Sites behind aggressive bot protection may return a challenge page; those are free.

FAQ

How is this different from BuiltWith or Wappalyzer? There's no subscription and no per-seat pricing. You pay per website, and failed lookups are free. You also get DNS-level company tools, which website-only scanners miss.

Is it legal? It reads publicly available information only: the public homepage, robots.txt and public DNS records, the same data any browser or DNS resolver sees. You are responsible for how you use the results (e.g. GDPR/CAN-SPAM rules for outreach).

How fast is it? It analyses 25 websites in parallel by default (adjustable up to 100). A list of 1,000 websites typically finishes in 5-10 minutes; runs can go for up to 6 hours by default, so lists of tens of thousands are fine.

Can I schedule it? Yes. Use Apify Schedules to re-check a list daily or weekly and get notified when a company adopts a new tool.

Related tools by the same developer

• Company Enrichment: one call per domain returns profile, contacts, socials, tech stack, email provider, domain age and hosting.
• Website Contact Extractor: emails, phones and social profiles from company websites.
• Email Provider & DMARC Checker: Google Workspace vs Microsoft 365, SPF/DKIM/DMARC grade, spoofable domains.
• SEO & AI Visibility Audit: on-page SEO plus which AI crawlers (ChatGPT, Perplexity, Claude) a site blocks.
• Company Hiring Signals: open roles by department for any list of company domains.

Found a missed or wrong detection? Open an issue on the Actor's Issues tab with the domain.