What is WHOIS (Domain Name Lookup)?

WHOIS is a database that consists of mandatory information about a registered domain, or more precisely, the registered users of an Internet resource. A WHOIS information lookup is how we can find a wider range of information on a domain name, an IP address block and the domain availability status. This includes the contact information of the registrant, mailing address, phone number, email address, domain created date, updated date, expiration date as well as the nameservers the domain is using and much more.

What is WHOIS Privacy Protection?

It is also called domain privacy. We know how damaging data breaches can be in this century, therefore, businesses take domain privacy protection seriously. WHOIS privacy protection is a service to protect domain registries/' personal information from being searched in the WHOIS records. Under the WHOIS privacy protection, some domain registries allow domain owners to hide certain details in their public WHOIS records. The contact information in a WHOIS record can be hidden from the rest of the world using a "private registration" service offered by some registrars.

Free WHOIS - Domain WHOIS Lookup

At IP2WHOIS.com, we simplify domain intelligence with fast, accurate WHOIS lookups tailored for professionals. Instantly access critical domain data—such as registrant details, registrar records, key dates, and status—whether you're running a single query or monitoring thousands of domains across the web.

Choose our intuitive Domain WHOIS Lookup Tool or harness the flexibility of our Hosted Domain API to identify domains associated with any IP address. Ideal for cybersecurity analysts, researchers, and fraud investigators, IP2WHOIS helps you streamline investigations and automate domain tracking with ease and confidence.

Two Powerful APIs. One Seamless Experience.

Domain WHOIS API

Retrieve domain ownership, registrar, key dates, location and status. Perfect for domain tracking, research, and compliance.

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Hosted Domain API

Discover all domains hosted on a specific IP address. Ideal for network mapping, threat intel & hosting insights.

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Why Choose IP2WHOIS

Real-time data with global TLD coverage

Fast RESTful API with JSON responses

Supports reverse IP lookups for IPv4 and IPv6

Built for automation, analysis & scalability

99.9% uptime & robust infrastructure

Developer-first: Easy integration with clear docs

Who Uses IP2WHOIS

Cybersecurity Teams

Detect malicious domains and monitor threat actors.

Investigators & Analysts

Uncover hidden domain ownership and connections.

Enterprises & SaaS Providers

Ensure domain legitimacy and reduce fraud.

Researchers & Developers

Integrate domain data into tools, reports, and platforms.

Understanding WHOIS & Domain Privacy

WHOIS is a public database that stores key information about registered domain names, such as the owner's contact details, registrar, registration dates, and name servers. When someone registers a domain, this data is collected by the registrar and made publicly available as required by ICANN (Internet Corporation for Assigned Names and Numbers). A WHOIS lookup lets anyone check domain availability or view details about who owns a domain and when it was registered or will expire.

WHOIS Privacy Protection, also known as domain privacy, is a service that hides a domain owner's personal information from public WHOIS records. Instead of showing real contact details, it replaces them with generic or proxy information. This helps protect domain owners from spam, data harvesting, and identity theft, while still meeting ICANN’s requirements.