WhoisXML API WHOIS API vs OpenRDAP

WhoisXML API WHOIS API9.2Visit OOpenRDAP8.4Visit

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

O OpenRDAP #6 in WHOIS Lookup Tools 8.4/10 Free plan Free plan✓ 1 of 3 features Visit OpenRDAP

• WhoisXML API WHOIS API fits best

  API users needing broad lookup and integrations

• OpenRDAP fits best

  Technical users wanting open-source RDAP

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Side by side

Feature	WhoisXML API WHOIS API 9.2/10 Visit ↗	OOpenRDAP 8.4/10 Visit ↗
At a glance
Editor score	9.2	8.4
Ranking	#2 in WHOIS Lookup Tools	#6 in WHOIS Lookup Tools
Best for	API users needing broad lookup and integrations	Technical users wanting open-source RDAP
Pricing model	Free plan + paid	Free
Starting price	Free plan	Free plan
Free plan	✓	✓
Free trial	—	—
Deployment	Cloud	Cloud, Self-hosted, Browser extension
Platforms	Web	Web
Support	Email, Phone, Docs	Email, Docs
Built for	Small business, Mid-market, Enterprise	Solo, Small business, Mid-market, Enterprise
Features WhoisXML API WHOIS API 2/3 · OpenRDAP 1/3
Bulk lookup	✓ (best)	Not checked yet
Historical WHOIS	—	Not checked yet
RDAP support	✓	✓
Specs
API access	Full	Full
Monthly lookup limit	Not checked yet	Not checked yet
Export formats	JSON, XML	text, JSON, raw JSON, WHOIS style
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	Supports domain, IP, ASN, nameserver, entity, URL, and search queries Offers web, API, and self-hosted access with full RDAP support Provides text, JSON, raw, and WHOIS-style output formats
Cons	Historical WHOIS is not included Bulk lookup uses a separate Bulk WHOIS API Paid access is handled through a contact form	Its primary interface is a command-line client It has no AI-assisted features WHOIS-style output applies to domain queries
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 →	OpenRDAP is an open-source command-line client written in Go for querying Registration Data Access Protocol servers. It is aimed at technical users who need domain, IP address, autonomous system, nameserver, entity, URL, and search lookups… 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

• OpenRDAP — where it wins

  • Supports domain, IP, ASN, nameserver, entity, URL, and search queries
  • Offers web, API, and self-hosted access with full RDAP support
  • Provides text, JSON, raw, and WHOIS-style output formats

  Where it doesn't

  • Its primary interface is a command-line client
  • It has no AI-assisted features
  • WHOIS-style output applies to domain queries

• 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 →
• OOpenRDAP8.4/10 · Free plan

  A flexible, open-source RDAP client for technical users who want control over queries and output.

  Visit OpenRDAPFull verdict →