Description

WhoisJSON is a domain intelligence API platform that consolidates six endpoints under a single API token — no separate subscriptions, no credential juggling.
What's included in every plan:

WHOIS lookup — registrar, creation/expiry dates, nameservers, EPP status, contacts. 1,500+ TLDs with automatic RDAP enrichment (domain age, days to expiry, status analysis)
DNS records — A, AAAA, MX, TXT, CNAME, NS, SOA, DMARC, SPF, CAA, BIMI in a single call
SSL certificate check — issuer, validity window, SANs, SHA-256 fingerprint for change detection
Domain availability — real-time registration status powered by live WHOIS/RDAP data
Subdomain discovery — 800+ patterns, wildcard detection, parallel DNS resolution
Domain monitoring — WHOIS change alerts, DNS/SSL tracking, expiry reminders

Who uses it:
Cybersecurity teams building phishing detection and attack surface management pipelines, developers integrating domain intelligence into SaaS products, DevOps engineers monitoring SSL expiry and DNS propagation, brand protection teams tracking lookalike registrations.
Pricing:
Free tier — 1,000 requests/month across all six endpoints, no credit card. Paid plans from $10/month (Pro, 30K req) up to $600/month (Atlas, 900 RPM, ~31M req/month). All plans include JSON and XML output.
MCP Server available — query WHOIS, DNS, SSL, and domain availability directly from Claude, Cursor, or Windsurf via the WhoisJSON MCP server.