When learning how to bring your website online, you will inevitably come across the WHOIS lookup service. It is a searchable, public directory of every domain name currently registered in the world. Even if you have never heard the term, it is worth understanding what it does and how it affects you as a domain owner.
Last reviewed: 27 July 2026. WHOIS, and its modern successor RDAP (Registration Data Access Protocol), are governed by ICANN policy and by the relevant country registries. This guide is written for Noiz customers and is kept current against those policies. It complements, and does not replace, the official documentation linked below.
Official Documentation Reference
- ICANN Registration Data Lookup Tool (the official RDAP-based lookup).
- ICANN: About WHOIS and RDAP.
- ZA Domain Name Authority (policy for .za domains such as .co.za).
What exactly is a WHOIS lookup, and why would I use it?
WHOIS is a free public database, and a search service that lets you look up the publicly listed information associated with an already registered domain name. It is regulated by ICANN. The information is passed to the registry database by your registrar when you register a domain name.
A WHOIS search returns no registration information if a domain is not yet registered, which usually means the name is available for public registration.
The first reason you might use the WHOIS service, then, is to check whether a domain is available before you settle on a name for your website. You can do this directly from the Noiz domain search.
Another reason is to report abuse to a website or domain administrator, or to get in touch with a domain owner.
Why does the WHOIS database exist?
At its inception, the database was meant simply as a domain directory, listing the contact information of anyone transmitting data over the early stages of what is now the internet. This was before the advent of search engines.
What information is stored in the WHOIS database?
When a domain name is registered, the registrant (probably you) has to supply contact information. This information must be accurate and true: supplying false details when you register a domain can lead to the domain being suspended or cancelled under ICANN policy.
Registrant information typically includes:
- Name.
- Postal address.
- Phone number.
- Email address.
- Nameservers.
So is all of my information public?
Historically, yes. By default, a registered domain recorded the registrant, the registrar, the technical and abuse contacts, the registrant email address, the nameservers and more.
That has changed. Since the introduction of modern data-protection rules, most personal contact details for individual registrants are now redacted by default in the public record for generic top-level domains (such as .com and .org), and are only released by the registrar in response to specific, justified requests. Organisation and technical fields, along with the nameservers and registration dates, generally remain visible.
If you want to keep even more of your details out of the public record, many registrars and hosting providers offer a paid domain privacy (WHOIS privacy) service that substitutes proxy contact details for your own. Noiz customers can enable this on eligible domains from the client area. Note that some registries, including the .za registry, do not permit WHOIS privacy on their domains.
How to perform a WHOIS lookup
There are a few ways to perform a WHOIS lookup. This guide covers two:
- An online WHOIS service through a web browser.
- The
whoiscommand from a Linux command line.
Using an online WHOIS service
The most authoritative source is ICANN itself. Point your browser to the ICANN Registration Data Lookup Tool, enter the domain name you want to search, complete the captcha and click Lookup to view the results. This tool now uses RDAP, the structured successor to the original WHOIS protocol, which ICANN has been retiring since early 2025.
The ICANN tool does not cover .co.za domains. South Africa's old whois.co.za web lookup is now defunct, so for .za domains the command-line method below is the most reliable option, as it queries the correct .za registry server automatically.
Other general-purpose online WHOIS services include:
Using the whois command on Linux
From a Linux terminal, run the command (using noiz.co.za as an example, which you would replace with the domain you want to look up):
whois noiz.co.zaThe tool returns all of the public information available for that domain, and automatically contacts the right registry server for the domain's extension.
If the whois command is not installed, update your package lists and install it:
sudo apt update
sudo apt install whoisThen run the lookup again as shown above.
Summary
You now know what the WHOIS database is, what it stores, how to search it with both a browser and the command line, and how modern privacy rules and RDAP have changed what you will actually see in the results.
If you have registered a domain with Noiz and need help checking or updating its public records, or enabling domain privacy, the Noiz support team is happy to assist from your client area.
