WhoisXML API WHOIS API vs RDAP API

WhoisXML API WHOIS API9.2Visit RDAP API8.2Visit

Higher score WhoisXML API WHOIS API #2 in WHOIS Lookup Tools 9.2/10 Free plan Free plan✓ 2 of 3 features Visit WhoisXML API

vs

RDAP API #7 in WHOIS Lookup Tools 8.2/10 7-day trial Free trial✓ 2 of 3 features Visit RDAP API

• WhoisXML API WHOIS API fits best

  API users needing broad lookup and integrations

• RDAP API fits best

  Developers needing a polished RDAP API

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Side by side

Feature	WhoisXML API WHOIS API 9.2/10 Visit ↗	RDAP API 8.2/10 Visit ↗
At a glance
Editor score	9.2	8.2
Ranking	#2 in WHOIS Lookup Tools	#7 in WHOIS Lookup Tools
Best for	API users needing broad lookup and integrations	Developers needing a polished RDAP API
Pricing model	Free plan + paid	Paid
Starting price	Free plan	$9/mo
Free plan	✓ (best)	—
Free trial	—	7 days
Deployment	Cloud	Cloud
Platforms	Web	Web
Support	Email, Phone, Docs	Email, Docs
Compliance	GDPR, PCI DSS	GDPR, 2FA
Integrations	14 integrations	6 integrations
Built for	Small business, Mid-market, Enterprise	Small business, Mid-market, Enterprise
Features WhoisXML API WHOIS API 2/3 · RDAP API 2/3
Bulk lookup	✓	✓
Historical WHOIS	—	Not checked yet
RDAP support	✓	✓
Specs
API access	Full	Full
Monthly lookup limit	Not checked yet	30000 /mo
Export formats	JSON, XML	Not checked yet
Our review
Pros	Supports WHOIS, RDAP, or automatic protocol selection Returns parsed and raw data in JSON or XML Connects with security, data, and workflow platforms	RDAP with WHOIS fallback for broader domain coverage Bulk lookups support up to 10 domains per request Official SDKs plus an MCP server for AI-agent lookups
Cons	Historical WHOIS is not included Bulk lookup uses a separate Bulk WHOIS API Paid access is handled through a contact form	No permanent free subscription plan Bulk requests are capped at 10 domains Rate limits vary by paid plan
Our verdict	WhoisXML API WHOIS API is a hosted REST service for retrieving registration data about domains, IPv4 and IPv6 addresses, and email addresses. It is aimed at developers, security teams, analysts, and workflows that need programmatic lookup… Read the review →	RDAP API is a hosted REST API for developers who need domain registration and network lookup data in a consistent format. It queries domain registrations through RDAP and uses WHOIS fallback for TLDs without RDAP servers. The service also… Read the review →

Strengths and trade-offs

• WhoisXML API WHOIS API — where it wins

  • Supports WHOIS, RDAP, or automatic protocol selection
  • Returns parsed and raw data in JSON or XML
  • Connects with security, data, and workflow platforms

  Where it doesn't

  • Historical WHOIS is not included
  • Bulk lookup uses a separate Bulk WHOIS API
  • Paid access is handled through a contact form

• RDAP API — where it wins

  • RDAP with WHOIS fallback for broader domain coverage
  • Bulk lookups support up to 10 domains per request
  • Official SDKs plus an MCP server for AI-agent lookups

  Where it doesn't

  • No permanent free subscription plan
  • Bulk requests are capped at 10 domains
  • Rate limits vary by paid plan

• WhoisXML API WHOIS API9.2/10 · Free plan

  A broad lookup API with RDAP, parsed data, integrations, and a free tier.

  Visit WhoisXML APIFull verdict →
• RDAP API8.2/10 · 7-day trial

  A developer-focused lookup API with normalized JSON, bulk requests, and broad lookup coverage.

  Visit RDAP APIFull verdict →