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AnotterToolbox
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WHOIS Lookup

Look up domain registration information

What is WHOIS?

WHOIS (pronounced "who is") is a query/response protocol that provides information about registered internet resources. For domain names, a WHOIS lookup reveals who registered the domain, when it expires, which company serves as the registrar, and which nameservers handle its DNS.

WHOIS was originally a simple text-based protocol developed in the 1970s. Today, our tool uses RDAP (Registration Data Access Protocol), the modern JSON-based replacement that provides structured, machine-readable data and better handles privacy regulations.

How to use the WHOIS Lookup

  1. Enter a domain name — just the bare domain (like example.com), without https:// or paths
  2. Click WHOIS — the tool queries the appropriate RDAP server for that TLD automatically
  3. Review the results — see registration dates, registrar information, nameservers, and domain status codes

Note that due to GDPR and other privacy regulations, registrant contact information is frequently redacted. This is normal and expected for most domains registered since 2018.

Understanding WHOIS results

Registration date — when the domain was first registered. A long-standing domain generally signals more trustworthiness than a freshly registered one.

Expiry date — when the domain registration runs out. Important for monitoring your own domains and for assessing other domains you may want to acquire.

Registrar — the company through which the domain is registered (Namecheap, GoDaddy, Google Domains, etc.). The registrar handles billing and domain transfers.

Nameservers — the DNS servers responsible for the domain. Changing nameservers updates where DNS queries for the domain are sent.

Domain status — codes like clientTransferProhibited (transfer locked), clientUpdateProhibited (changes locked), and active (normal operation).

Common WHOIS use cases

Domain research — before buying a domain, check if it's registered, when it expires (it may be available soon), and who currently owns it.

Cybersecurity investigation — security researchers use WHOIS to investigate suspicious domains, phishing sites, and malicious infrastructure.

Brand protection — companies monitor WHOIS for newly registered domains that might infringe on their trademarks.

Due diligence — when evaluating a website or online business, WHOIS data can reveal how long the domain has been registered and other trust signals.

Frequently Asked Questions

What is WHOIS?+
WHOIS is a protocol used to query databases that store registered users of internet resources, most commonly domain names. A WHOIS lookup returns information about who owns a domain, when it was registered, when it expires, which nameservers it uses, and contact details for the registrant (though these are often redacted for privacy under GDPR).
What is RDAP and how is it different from WHOIS?+
RDAP (Registration Data Access Protocol) is the modern replacement for WHOIS. It returns structured JSON data instead of unformatted text, supports authentication for access to non-public data, and is designed to handle GDPR requirements more gracefully. Our tool uses RDAP, which is now the preferred protocol for domain registration data.
Why is registrant information often hidden or redacted?+
Under GDPR (General Data Protection Regulation) in Europe and similar privacy laws elsewhere, domain registrars are required to protect the personal information of domain registrants. As a result, contact details like name, email, phone, and address are often replaced with redacted placeholders or a privacy service's contact information.
What does "clientTransferProhibited" status mean?+
Domain status codes indicate what operations are allowed on the domain. clientTransferProhibited means the domain cannot currently be transferred to another registrar — a common security setting. clientDeleteProhibited prevents deletion. clientUpdateProhibited prevents changes. These are set by the registrar as security measures.
How do I find out if a domain is available to register?+
WHOIS/RDAP lookups will return an error or empty result if a domain is not registered. You can also use domain registrar websites (Namecheap, Porkbun, GoDaddy) which check availability in real time across multiple TLDs simultaneously and let you register immediately.
What does domain expiry mean and should I be concerned?+
Every domain registration has an expiry date. After expiry, there's typically a grace period where the original owner can still renew. After the grace period, the domain enters a "redemption period" where renewal is expensive. Finally, it becomes available for anyone to register. Domain expiry is important to monitor — expired domains can be bought by competitors or domain squatters.
Can I look up WHOIS data for any domain?+
You can look up WHOIS/RDAP data for any domain that has a corresponding RDAP service. Most major TLDs (.com, .net, .org, .dev, .io, etc.) support RDAP. Some country-code TLDs (ccTLDs) may have limited or no RDAP support. Our tool automatically finds the right RDAP service for each TLD.
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