Tech Stack Detector & Domain Lookup: DNS, WHOIS, Email, SSL

Tech stack detector and bulk domain lookup: find out what technology a website uses, who hosts its email, and its WHOIS, DNS and SSL details, for thousands of domains at once.

Paste in a list of domains, website URLs or work emails. For each company you get back one clean JSON row with its:

• Website tech stack. 135+ technologies: CMS, e-commerce platform, framework, hosting/CDN, analytics, ad pixels, CRM and marketing automation, live chat, payments, cookie consent and more.
• Email provider. Google Workspace, Microsoft 365, Zoho, Proofpoint, Mimecast and others, detected from the MX records.
• Email sending tools found in SPF: SendGrid, Mailchimp, HubSpot, Salesforce, Amazon SES, Zendesk, Klaviyo and more.
• Email security grade (A–F) based on SPF and DMARC policy. It's a good opener for security and deliverability outreach.
• SaaS tools the company has verified in DNS, such as Atlassian, Slack, OpenAI, Anthropic, DocuSign, Stripe, Okta, Notion, Zoom and more. Most other tools miss this buying signal.
• Domain registration from the official RDAP registry: registrar, creation and expiry dates, and domain age in days.
• SSL certificate: issuer, validity dates, days until expiry, and TLS protocol.
• DNS provider (Cloudflare, Route 53, GoDaddy, etc.) plus the raw A/AAAA/MX/NS/TXT/CAA records.
• Company social profiles linked from the homepage: LinkedIn company page, X, Facebook, Instagram, YouTube, GitHub, TikTok, Crunchbase and Discord.
• Site basics: title, meta description, language, redirects, HTTPS, security headers, robots.txt, sitemaps, and whether the site publishes an llms.txt for AI crawlers.

No API keys and no login. It's fast, at roughly 1–3 seconds per domain with up to 50 in parallel. Domains that don't exist and invalid entries are free.

Who uses this

• Sales and lead-gen teams. Qualify and segment account lists by technology ("everyone on Shopify + Klaviyo", "companies on Microsoft 365 without DMARC"), then enrich a CRM export.
• Agencies. Find prospects on outdated stacks or with weak email security, expiring SSL, or no analytics.
• Security and deliverability consultants. Bulk SPF/DMARC audits of customer or prospect domains.
• Investors and market researchers. Measure technology adoption across a list of companies, and check domain age as a maturity signal.
• AI agents and automations. Call it from n8n, Make, Zapier or Apify MCP to answer "what does this company use?" in one call.

Input

{
  "domains": ["stripe.com", "https://www.notion.so/pricing", "jane@apify.com"],
  "includeWebsite": true,
  "includeRegistration": true,
  "includeTls": true,
  "respectRobotsTxt": true,
  "maxConcurrency": 10
}

The tool accepts bare domains, full URLs and email addresses, normalizes them to the domain, and removes duplicates. Turn off includeWebsite for a pure DNS, email and registration run.

Output (shortened example)

{
  "domain": "apify.com",
  "exists": true,
  "dnsProvider": "Amazon Route 53",
  "email": {
    "acceptsEmail": true,
    "mailboxProvider": "Google Workspace",
    "spf": { "present": true, "allPolicy": "softfail", "senders": ["Amazon SES", "Google Workspace", "HubSpot", "Mailgun"] },
    "dmarc": { "present": true, "policy": "reject", "pct": 100, "rua": true },
    "securityGrade": "A"
  },
  "verifiedServices": ["Google Search Console / Workspace", "OpenAI"],
  "registration": { "registrar": "Amazon Registrar, Inc.", "createdAt": "2009-…", "expiresAt": "…", "domainAgeDays": 6340 },
  "tls": { "issuer": "Amazon", "daysUntilExpiry": 97, "protocol": "TLSv1.3" },
  "website": {
    "finalUrl": "https://apify.com/",
    "title": "Apify: Marketplace of ready-to-run tools for AI",
    "technologies": [
      { "name": "Next.js", "category": "JavaScript framework", "evidence": "html" },
      { "name": "HubSpot", "category": "Marketing automation", "evidence": "html" },
      { "name": "Intercom", "category": "Live chat", "evidence": "html" }
    ],
    "socialProfiles": { "linkedin": "https://www.linkedin.com/company/apify", "github": "https://github.com/apify" },
    "llmsTxt": true
  }
}

The Overview table view in the dataset tab flattens the key columns for CSV and Excel export.

Pricing

Pay per result. You are charged only for domains that exist:

Event	Price
Domain analyzed (full profile)	$0.004 (that's $4 per 1,000 domains)

Non-existent domains, invalid input lines and duplicates cost nothing. Use the maximum-cost-per-run setting to cap your spend, and the run stops cleanly when it reaches the cap.

How it works and data sources

• DNS: standard public DNS queries. If the system resolver looks unreliable, the tool automatically falls back to DNS-over-HTTPS (Cloudflare, then Google).
• Registration: the official RDAP protocol, the ICANN-mandated successor to WHOIS, using IANA's bootstrap registry. Some country TLDs (for example .so) don't offer RDAP and return null.
• TLS: a single TLS handshake to port 443.
• Website: robots.txt, then the homepage, then /llms.txt. That's three light requests per domain, with a clearly identified user agent. The tool respects robots.txt by default. It doesn't crawl, doesn't log in, and doesn't collect personal data.
• Fingerprints are an original, curated signature set covering headers, cookies, script URLs, HTML markers and generator tags.

FAQ

Is this legal? The tool reads only public DNS, public registry (RDAP) data and a site's public homepage, the same information any browser or mail server sees. It honors robots.txt and doesn't collect personal data. As always, use the results in line with your local laws, such as GDPR rules for outreach.

Why is a technology missing? Some sites load scripts only after cookie consent or user interaction, so a single-page fetch can't see them. DNS-based signals (email provider, SPF senders, verified SaaS) don't have that limitation.

Do you return contact emails or people? No. This tool is company-level only.

Feature requests and bugs: please open an issue in the Issues tab. We monitor issues and ship fixes quickly.

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