OpenRDAP

At a glance

• Editor score
  8.4 / 10
• Pricing
  Free plan
• Best for
  Technical users wanting open-source RDAP
• Free plan
  Yes
• Paid from
  Free
• API access
  Full
• Facts checked
  20 Sep 2026

• 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

Our verdict on OpenRDAP

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 through web, API, or self-hosted access. Automatic query-type detection helps route several query classes, while the project also provides a Go library, a browser-based demo, and the rdap.net redirecting RDAP service.

Its main strength is query and output flexibility. RDAP bootstrap support helps identify the relevant service, and an optional on-disk bootstrap cache can support repeated work. Users can set a custom query timeout and use X.509 client authentication where required. Results are available as text, JSON, raw server responses, or WHOIS-style output for domain queries, making OpenRDAP suitable for command-line workflows, scripts, and systems that need structured responses rather than a browser-only lookup experience.

OpenRDAP is available as open-source software with a free plan, and its published product details show no paid tier structure. That makes it a fit for users who value self-hosting, API access, and control over how registration data is queried and displayed. It is less suited to buyers looking primarily for a polished, nontechnical interface or AI-assisted investigation features. Users who need a focused RDAP client with broad query coverage and multiple response formats should consider it; those who prefer a guided visual workflow may want a different type of lookup tool.

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OpenRDAP pricing

OpenRDAP fact sheet

Alternatives to OpenRDAP

• WhoisDataCenterA broad WHOIS research service with useful free allowances and paid data products.9.4
• WhoisXML API WHOIS APIA broad lookup API with RDAP, parsed data, integrations, and a free tier.9.2
• WWhoxyA pay-as-you-go WHOIS platform for high-volume lookups, history, reverse search, and datasets.9.0

See all OpenRDAP alternatives →

OpenRDAP vs the competition

• OOpenRDAP vs WhoisDataCenter
• OOpenRDAP vs WhoisXML API WHOIS API
• OWOpenRDAP vs Whoxy
• OOpenRDAP vs WhoisJSON API
• OOpenRDAP vs WhoisFreaks WHOIS API
• OOpenRDAP vs RDAP API

Compare OpenRDAP with any tool side by side →

Featured on iTechGuides

OpenRDAP is listed in our WHOIS Lookup Tools directory. Add the badge to your site — it links back to this page.

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Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

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Last updated 7 Oct 2026 · How we research and update