WHOIS Lookup

What Is a WHOIS Lookup?

A WHOIS lookupqueries public registration databases to retrieve detailed information about a domain name. Every domain registered on the internet has associated WHOIS records maintained by the domain registry and registrar. These records include the domain's registrar, registration and expiration dates, nameserver configuration, domain status codes, and — when not privacy-protected — the registrant's contact information.

The WHOIS system was created in the 1980s as part of ARPANET and has been the standard protocol for querying domain registration data ever since. DNS Robot's WHOIS lookup tool uses the modern RDAP (Registration Data Access Protocol) as its primary data source, with traditional WHOIS as a fallback for maximum TLD coverage. RDAP delivers structured JSON responses over encrypted HTTPS connections, replacing the legacy plain-text WHOIS format.

How to Do a WHOIS Lookup

Performing a WHOIS domain lookup with DNS Robot is straightforward. Our tool handles the complexity of querying the correct registry server for any TLD automatically.

What Does a WHOIS Lookup Reveal?

A comprehensive WHOIS domain lookup returns several categories of registration data. Understanding each field helps you assess domain ownership, security, and configuration.

Domain Name Lookup: Is It Taken, Who Owns It, and When Does It Expire?

Most people run a domain name lookup to answer one of three questions, and each answer sits in a different part of the record. Here is where to look, and what the field actually means.

Every lookup updates the address bar with ?domain=, so you can bookmark a whois domain search or send the exact result to a colleague. The same box accepts a full URL, an internationalised name, or an IP address.

RDAP vs Traditional WHOIS Protocol

DNS Robot uses the RDAP protocol (Registration Data Access Protocol) as its primary data source, which is the official ICANN-endorsed replacement for the legacy WHOIS protocol. Here's why RDAP is superior for modern WHOIS lookups.

IP WHOIS Lookup: Who Owns an IP Address?

Type an IPv4 or IPv6 address into the same box and the tool runs an IP WHOIS lookup instead. Domain names are managed by registries and registrars; IP address blocks are allocated by the five Regional Internet Registries, and each one publishes its own RDAP database. The tool reads the IANA bootstrap file to find which registry holds the block, then asks that registry directly.

An IP record tells you the network name, the exact address range and CIDR, the organisation that holds it, the country of assignment, and the abuse contact to use when an address is attacking your server or sending spam. It does not tell you which websites are hosted on the address, and it does not give a street-level location. For geolocation and ISP details use IP Lookup, for the announcing network use ASN Lookup, to map an address back to a hostname use Reverse DNS, and to see whether it is listed on spam blocklists use the IP blacklist checker.

WHOIS Lookup Use Cases

A WHOIS search serves many purposes across security, business, and technical operations. Here are the most common reasons professionals perform WHOIS lookups.

Understanding Domain Status Codes

When you perform a WHOIS lookup, the results include EPP (Extensible Provisioning Protocol) status codes. These codes control what actions can be performed on a domain and provide insight into its current state.

A code beginning with client was set by the registrar, usually at the owner's request. A code beginning with server was set by the registry and only the registry can remove it. The tool shows every code as a chip; hover one for its meaning.

A site that suddenly fails with DNS_PROBE_FINISHED_NXDOMAIN for every visitor is a WHOIS problem more often than a DNS problem: check for clientHold, serverHold or an expired date before touching DNS records. The full diagnosis is in DNS_PROBE_FINISHED_NXDOMAIN explained, and every code is covered in the WHOIS lookup guide.

WHOIS Privacy and GDPR

Since the EU's General Data Protection Regulation (GDPR) took effect in May 2018, most WHOIS records now show redacted personal information. Registrars are required to protect registrant data by default, replacing names, emails, phone numbers, and addresses with privacy-protected placeholders.

Even with WHOIS privacy enabled, a WHOIS search still reveals valuable data: the registrar name, registration and expiration dates, nameservers, domain status codes, and DNSSEC configuration. For legitimate purposes like trademark enforcement, registrars provide WHOIS disclosure request processes to contact domain owners through anonymized email forwarding.

For a field-by-field walkthrough of a redacted record, every EPP status code, the 2025 switch from port-43 WHOIS to RDAP, and seven ways to reach a domain owner when the contact fields are hidden, read our WHOIS lookup guide.

When WHOIS Is Redacted: How to Find the Domain Owner Anyway

Redaction removed the name and email, but a domain leaves other fingerprints. Work through these in order; most owners are identified by the third step.

• Read what is not redacted. Organisation, state and country often remain, and the registrar itself narrows things: MarkMonitor or CSC means a large corporation, Cloudflare Registrar usually means a developer or startup.
• Use the registrar relay. Every registrar must give you a way to reach the registrant, either an anonymised forwarding address or a web form linked from the record. Offers to buy get answered far more often than questions.
• Check the SSL certificate. Organisation-validated certificates carry the legal company name. Run the domain through the SSL checker and read the subject field.
• Look at DNS. The SOA record names the zone administrator, and TXT records reveal the mail provider and verification tokens for Google, Microsoft and Facebook.
• File a request. For a legal need such as fraud or trademark abuse, ICANN's Registration Data Request Service routes a disclosure request to the registrar for any gTLD.

The SSL checker, DNS lookup and subdomain finder cover the technical steps; the WHOIS lookup guide walks through all seven with examples.

WHOIS Lookup Best Practices

WHOIS Lookup by Country: What ccTLD Registries Publish

ICANN's rules bind generic extensions such as .com and .org. Country-code registries set their own policy, and a whois by domainquery on a ccTLD can return anything from a validated company identity to almost nothing. The tool queries each registry's RDAP server where one exists and falls back to the registry's port-43 WHOIS where it does not.

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