WhoisDataCenter vs RDAP API

WhoisDataCenter9.4Visit RDAP API8.2Visit

Higher score WhoisDataCenter #1 in WHOIS Lookup Tools 9.4/10 Free plan Free plan✓ 1 of 3 features Try WhoisDataCenter

vs

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

• WhoisDataCenter fits best

  Investigators needing current and historical WHOIS

• RDAP API fits best

  Developers needing a polished RDAP API

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Side by side

Feature	WhoisDataCenter 9.4/10 Visit ↗	RDAP API 8.2/10 Visit ↗
At a glance
Editor score	9.4	8.2
Ranking	#1 in WHOIS Lookup Tools	#7 in WHOIS Lookup Tools
Best for	Investigators needing current and historical WHOIS	Developers needing a polished RDAP API
Pricing model	Free plan + paid	Paid
Starting price	—	$9/mo
Free plan	✓ (best)	—
Free trial	—	7 days
Deployment	Cloud	Cloud
Platforms	Web	Web
Support	Email, Tickets, Docs · 24/7	Email, Docs
Compliance	GDPR	GDPR, 2FA
Built for	Small business, Mid-market, Enterprise	Small business, Mid-market, Enterprise
Features WhoisDataCenter 1/3 · RDAP API 2/3
Bulk lookup	Not checked yet	✓ (best)
Historical WHOIS	✓ (best)	Not checked yet
RDAP support	Not checked yet	✓ (best)
Specs
API access	Full	Full
Monthly lookup limit	Not checked yet	30000 /mo
Export formats	CSV, JSON	Not checked yet
Our review
Pros	Historical WHOIS records support domain research over time. Reverse lookup searches multiple registrant and DNS identifiers. APIs, lifecycle feeds, and CSV/JSON delivery support workflows.	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	Free query allowances vary by lookup product. Larger databases and recurring feeds are sold separately. Its broad data offering may exceed simple lookup needs.	No permanent free subscription plan Bulk requests are capped at 10 domains Rate limits vary by paid plan
Our verdict	WhoisDataCenter is a domain-intelligence service for cybersecurity teams, brand-protection agencies, researchers, legal teams, businesses, and other data-driven organizations. It combines current WHOIS lookups with historical records,… 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

• WhoisDataCenter — where it wins

  • Historical WHOIS records support domain research over time.
  • Reverse lookup searches multiple registrant and DNS identifiers.
  • APIs, lifecycle feeds, and CSV/JSON delivery support workflows.

  Where it doesn't

  • Free query allowances vary by lookup product.
  • Larger databases and recurring feeds are sold separately.
  • Its broad data offering may exceed simple lookup needs.

• 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

• WhoisDataCenter9.4/10 · Free plan

  A broad WHOIS research service with useful free allowances and paid data products.

  Try WhoisDataCenterFull 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 →