API & Integrations

Understanding WHOIS Data Fields

A complete reference for every field returned by the WhoisExtractor API - what each field means, where the data comes from, and when to expect null values.

Understanding WHOIS Data Fields
April 11, 2026 API & Integrations WhoisExtractor Team

What Is WHOIS Data?

WHOIS is a protocol that allows anyone to query the registration records of a domain. Domain registrars and registries are required to publish registration information, though many fields may be hidden when a registrant uses a WHOIS privacy service.

Core Fields

domain

The domain name queried, in lowercase with no trailing dot. Always present.

registrar

The name of the registrar through which the domain is registered (e.g. GoDaddy, Namecheap, Google Domains). Usually present; may be null for country-code TLDs (ccTLDs) that don't publish registrar information.

registrar_url

The registrar's website. May be null.

registrar_iana_id

The IANA registrar ID. Integer. May be null for ccTLD registries.

Date Fields

created_at

The date the domain was first registered. Format: YYYY-MM-DD. Present for most domains; may be null for older ccTLDs that don't publish creation dates.

updated_at

The date the registration record was last updated. Format: YYYY-MM-DD.

expires_at

The date the registration expires. Format: YYYY-MM-DD. null if the registry does not publish expiry dates.

Registrant Fields

These fields describe the domain's owner. They are frequently null for domains using WHOIS privacy protection.

registrant_name

The registered name of the owner (individual or organization).

registrant_email

The registrant's contact email. null for privacy-protected domains or domains under GDPR redaction.

registrant_organization

The registrant's organization name, if provided.

registrant_country

ISO 3166-1 alpha-2 country code (e.g. US, GB, DE).

Technical Fields

nameservers

An array of nameserver hostnames for the domain. Example: ["ns1.example.com", "ns2.example.com"]. Empty array if no nameservers are published.

status

An array of EPP status codes that describe the domain's current state. Codes are prefixed with either client (set by the registrar) or server (set by the registry).

Status Meaning
clientDeleteProhibited Registrar has locked the domain against deletion
clientTransferProhibited Registrar has locked the domain against outbound transfers
clientUpdateProhibited Registrar has locked the domain against contact/nameserver changes
serverDeleteProhibited Registry has locked the domain against deletion
serverTransferProhibited Registry has locked the domain against outbound transfers
serverUpdateProhibited Registry has locked the domain against contact/nameserver changes

When Values Are Null

Fields are null when:

  • The registry or registrar does not publish that data point
  • The registrant has enabled WHOIS privacy / proxy registration
  • GDPR data minimization rules apply (most .eu and ICANN-accredited registrars)
  • The domain is newly registered and the data hasn't propagated yet

Further Reading

whois api reference data fields

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