What It Is
WHOIS is a lookup service that tells you who a domain is registered with and some basic facts about it, such as when it was created and when it expires. It works like a public directory for domain names. For most domain endings, a newer protocol called RDAP officially replaced the older WHOIS system in 2025 and delivers the same information in a more modern format, but most people still call the lookup WHOIS.
Why It Matters for Your Business
WHOIS is useful when you want to check whether a domain you like is taken, find out when it expires, or confirm which registrar holds your own domain. For example, if you are not sure where your business domain was registered years ago, a quick WHOIS search usually tells you which company to contact.
Good to Know
Many registrars now hide personal details in WHOIS by default, which reduces spam and scam calls. If your name, phone and home address still show up, turn on domain privacy in your registrar account. It is also worth running a lookup on your own domain once a year to confirm the expiry date and registrar are what you expect.