Why can't this page perform a live WHOIS lookup?

Browsers cannot open raw TCP connections on port 43 (the WHOIS protocol port). There is no browser-native API for WHOIS queries. You must use a terminal command or a web service that proxies the request on the server side.

How do I run a WHOIS query in the terminal?

On Linux or macOS run: whois example.com or whois 8.8.8.8. On Windows, install Sysinternals Whois or use the Windows Subsystem for Linux (WSL). The whois command is pre-installed on most Unix-like systems.

Why is contact information sometimes hidden?

Many registrars offer WHOIS privacy (also called domain privacy or proxy registration). The registrant's personal details are replaced with the registrar's contact info. GDPR compliance has also led European registrars to redact personal data by default.

What is the difference between a thin and thick WHOIS registry?

A thin registry (common for .com and .net) stores only the registrar name and name servers. A thick registry (common for country-code TLDs and newer gTLDs) stores the full registrant record in one place.

Which Regional Internet Registry handles my IP?

ARIN covers North America, RIPE NCC covers Europe and the Middle East, APNIC covers Asia-Pacific, LACNIC covers Latin America, and AFRINIC covers Africa. Each runs its own WHOIS service.

Is WHOIS data always accurate?

Not necessarily. Registrants can provide false information, and WHOIS privacy services mask real contact details. For legal matters, a formal request through the registrar or legal channels is more reliable.

Whois Lookup

Name: Whois Lookup
Availability: InStock
Author: Nham Vu

Understand WHOIS, get the terminal command, and use trusted public WHOIS lookup services — all in one place.

Run a WHOIS Query Yourself

The fastest way to query WHOIS is the built-in terminal command available on Linux and macOS.

Domain lookup

whois example.com

IP address lookup

whois 8.8.8.8

Windows (PowerShell via Sysinternals)

.\whois.exe example.com

Why No Live Lookup Here?

WHOIS uses a plain TCP connection on port 43. Web browsers cannot open raw TCP sockets, so there is no way for a purely client-side page to query a WHOIS server directly. The public services listed below use server-side proxies to do the actual TCP query and return the result over HTTPS.

Trusted Public WHOIS Services

IP WHOIS by Region (RIRs)

Each Regional Internet Registry operates its own WHOIS for IP blocks in its region.

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Summary

Understand WHOIS, get the terminal command, and use trusted public WHOIS lookup services — all in one place.

How it works

A WHOIS client opens a TCP connection to a WHOIS server (port 43).
It sends the domain name or IP address followed by a newline.
The server responds with a plain-text record containing registration data.
For gTLDs, ICANN operates a thin registry; registrar-specific data requires a second query to the registrar's WHOIS server.
IP address lookups go to the relevant Regional Internet Registry (ARIN, RIPE, APNIC, LACNIC, or AFRINIC).
Modern services wrap this TCP protocol in a web interface, returning the same data over HTTPS.

Use cases

Verify who owns a domain before purchasing or contacting the owner.
Check domain expiry dates to catch renewal deadlines.
Investigate spam or phishing sources by looking up an IP or domain.
Find name servers and registrar details when troubleshooting DNS.
Confirm a domain transfer completed by checking the registrar field.
Research domain age and history for SEO or due-diligence purposes.
Identify the hosting provider or abuse contact for an IP address.
Detect domain squatting by checking recent registration dates.

Frequently Asked Questions

Last updated: 2026-06-10 · Reviewed by Nham Vu