How the lookup works
Every top-level domain (.com, .org, .uk…) has one registry that keeps the list of its domains. The tool takes the ending of the name you enter, finds that registry's RDAP server in the list IANA publishes, and asks it for the domain. For .com and .net the registry keeps only the basics, so the tool also asks the registrar the registry names.
RDAP is the successor of the old WHOIS protocol: the same records, sent as structured data over HTTPS. ICANN made it the official source for generic domains such as .com in January 2025. Some country domains do not offer it yet; for those, the registry's website is the place to look.
The status codes are the locks and states the registry and registrar set on a domain. clientTransferProhibited, the most common one, is the registrar's transfer lock: it stops someone from moving the domain to another registrar without the owner unlocking it first.
Example
You want to move a site to a new server and check its domain first. The lookup shows it expires in 12 days and is locked with clientTransferProhibited. Renew it before you change anything, and ask the registrar to remove the lock only if you also want to move the domain itself.
Questions
What is the difference between WHOIS and RDAP?
Both give the registration record of a domain. WHOIS is the older protocol: plain text in a format that differs between registries. RDAP sends the same data as structured JSON over HTTPS, with standard fields and links between registry and registrar. For generic domains such as .com, RDAP has been the official source since January 2025.
Why is the owner's name hidden?
Data protection laws, the EU's GDPR above all, made registries and registrars stop publishing personal data in 2018. Many owners also use a privacy service that stands in for them. What is usually left is the registrar, the dates, the status, the name servers and sometimes the owner's organisation and country.
How do I find out who owns a domain?
Look it up here first: companies often show their organisation name. If the details are withheld, contact the owner through the registrar, which forwards messages or offers a contact form. For legal matters such as trademark claims, registrars disclose the data on a proper request.
What does clientTransferProhibited mean?
It is the registrar's transfer lock. The domain works normally, but it cannot be moved to another registrar until the owner removes the lock in the registrar's control panel. Most registrars set it by default to protect against domain theft.
What happens when a domain expires?
The details differ between registries. For .com and most generic domains, the registrar usually keeps it for a grace period in which the owner can still renew it, then it enters a redemption period of about 30 days in which only the owner can restore it for a fee, and after about five more days of pendingDelete anyone can register it.