WHOIS Lookup

Registration, DNS, hosting and SSL certificate for any domain — or the owner of an IP address or AS number.

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Usage

  • Check when your own domain renews so it never lapses.
  • See whether a domain you want is registered, and which other extensions are free.
  • Find the registrar to report abuse, phishing or spam.
  • Confirm nameservers and DNS records after moving a site to a new host.
  • Check SPF, DMARC and MTA-STS before chasing email delivery problems.
  • Spot an expiring, untrusted or mismatched SSL certificate.
  • Verify how old a website really is before trusting it.
  • Identify which network, company or AS owns an IP address.

Knowledge

Every domain name is held through a registrar (the company you pay) and recorded by a registry (the operator of the extension, such as Verisign for .com). Both publish registration data through WHOIS or its successor RDAP.

What a record shows

  • Dates: when the domain was created, last updated, and when it expires.
  • Status: EPP codes such as clientTransferProhibited or redemptionPeriod.
  • Nameservers: the DNS servers that answer for the domain.
  • DNSSEC: whether DNS answers are cryptographically signed.
  • Contacts: often redacted for privacy; the registrar abuse contact is usually public.

DNS and email records

The registry only records which nameservers answer for a domain. The records those servers publish — A/AAAA addresses, MX mail servers, TXT entries such as SPF and DMARC, and CAA certificate rules — decide where the website and email actually go. Each comes with a TTL, the time other resolvers may cache it.

IP addresses and AS numbers

IP blocks are allocated by five regional internet registries — ARIN, RIPE NCC, APNIC, LACNIC and AFRINIC — and their RDAP records show the network range, holder and abuse contact. Networks announce their blocks to the rest of the internet under an autonomous system (AS) number; routing data shows which AS announces an address and who it connects to.

FAQs

What is a WHOIS lookup?

WHOIS is the public record of who registered a domain name or IP address block. A lookup shows the registrar, key dates, status codes, nameservers and — where the registry publishes it — contact details. This tool also checks the domain's live DNS records, hosting network, website certificate and other extensions in the same search.

What is RDAP and how is it different from WHOIS?

RDAP (Registration Data Access Protocol) is the modern replacement for WHOIS. It returns structured data over HTTPS, so dates and statuses are consistent across registries. This tool uses RDAP first and falls back to classic WHOIS when a registry has no RDAP service.

Why is the owner's name hidden or "REDACTED"?

Privacy laws such as GDPR mean most registries no longer publish personal contact details. Many owners also use privacy services, which the tool names when it can recognise them. You can usually contact the owner through the registrar's abuse or contact form instead.

How do I find out when a domain expires?

Enter the domain and check the Expires date and countdown. For generic extensions such as .com, the tool also estimates the grace, redemption and pending-delete dates that follow if it is not renewed. Use "Add renewal reminder" to put the date in your calendar.

What do status codes like clientTransferProhibited mean?

They are EPP status codes set by the registrar or registry. "Transfer prohibited" locks the domain against transfer, "hold" means it is not active in DNS, and "redemption period" means it expired and can still be restored by the owner. Each code is explained next to it in the result.

Can I look up an IP address?

Yes. Enter an IPv4 or IPv6 address to see the network it belongs to, the organisation that holds it and the regional registry (ARIN, RIPE, APNIC, LACNIC or AFRINIC), plus its reverse DNS name, the AS that announces it and the routed prefix.

Can I look up an AS number?

Yes. Enter an autonomous system number such as AS13335 to see who holds it, the registry that assigned it, how many IPv4 and IPv6 prefixes it announces and how many upstream and downstream networks it connects to.

What do the email and security checks mean?

SPF lists the servers allowed to send mail for the domain, DMARC tells receivers what to do with mail that fails those checks, and MTA-STS forces encrypted delivery. CAA limits which certificate authorities may issue certificates, and DNSSEC signs DNS answers so they cannot be forged in transit.

What does the website and certificate check show?

It connects to the site over HTTPS and HTTP and reports the status code, redirects, response time, HSTS and server headers. For the certificate it shows whether browsers will trust it, who issued it, when it expires, every name it covers and the chain up to the root.

Is my lookup private?

Lookups are sent from the dab.tools server — to the official registries, Google Public DNS (with Cloudflare as a backup), RIPEstat for routing data and the Internet Archive — so your own IP address is not shared with them. We do not store what you search; recent lookups stay in your browser and can be cleared.