WHOIS lookup
See who a domain is registered with and when it expires, or who owns an IP address, straight from the registry over RDAP.
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The registry's record of a domain
A WHOIS lookup asks a registry what it knows about a name or an address. For a domain, that is the registry running its top-level domain: the registrar, the registration and expiry dates, the status codes that say whether it is locked or on hold, and the nameservers. For an IP address, it is one of the five regional internet registries: the organisation the address block is assigned to, the range and country, and where to report abuse. This tool uses RDAP, the structured protocol that replaced WHOIS text, and reads the registrable domain from any hostname, so www.example.co.uk looks up example.co.uk.
The expiry date is the number that matters. Registrations lapse quietly, on a card that expired or an inbox nobody reads, and Upcheck checks every website's registration daily and warns your team weeks before it does.
Three steps, no signup
- 01
Enter a domain or IP address
example.com, any hostname under it, or an IPv4 or IPv6 address.
- 02
We ask the registry over RDAP
Domains go to their TLD's registry, found through IANA's bootstrap file; addresses go to the regional registry that allocated them.
- 03
The registration comes back
For a domain, registrar, dates, and status with a verdict on expiry; for an address, who holds the block and how to reach them.
Frequently asked questions
What is the difference between WHOIS and RDAP?
The same data, in a different format. WHOIS is a 1980s protocol that returns free text, formatted differently by every registry and impossible to parse reliably. RDAP, the Registration Data Access Protocol, returns the same registration record as structured JSON over HTTPS, and is what registries are now required to run. This tool speaks RDAP; the answer is what a WHOIS query would give you, without the guesswork.
How do I find out who owns an IP address?
Enter the address above. Every public IP address belongs to a block that one of five regional internet registries (ARIN, RIPE NCC, APNIC, LACNIC, or AFRINIC) assigned to an organisation, usually an ISP, a hosting provider, or a large company. The lookup returns that organisation, the block's range and country, and its abuse contact. It identifies the network, not the person using the address at a given moment; only the network's operator can map an address to a customer.
Why doesn't the lookup show who owns the domain?
Because registries and registrars redact registrant contact details under privacy law, and have done since 2018 for most TLDs. What remains public is the registrar, the dates, the status codes, and the nameservers. To reach a domain's owner, most registrars offer a contact form or a forwarding address through their own site.
Why is there no expiry date for my domain?
Some registries publish RDAP but withhold the expiry date as a matter of policy; .de, .ch, and .nl are the best-known cases. The tool reports that honestly as 'no expiry published' rather than guessing. Your registrar's control panel still shows the date, and for those TLDs that is the place to watch.
What do the status codes mean?
They are EPP statuses set by the registrar or registry. clientTransferProhibited and similar locks are normal and good: they stop the domain being moved without you. clientHold or serverHold mean the name has been pulled from DNS, usually over an unpaid renewal or a failed contact verification, and the site is down now regardless of the expiry date. redemptionPeriod and pendingDelete mean the registration has already lapsed and is in the last window before the name is released.
Is this WHOIS lookup free?
Yes. No account, no limit on lookups by hand; scripted use is rate limited to be fair to the registries' RDAP servers. Upcheck's paid monitoring runs this lookup daily for every website you add and alerts your team at the thresholds you choose before the registration lapses.
One lookup shows the expiry date. Monitoring makes sure you don't miss it.
Add your domains to Upcheck and get alerted by email, Slack, Discord, Teams, or webhook weeks before a registration runs out.