WHOIS Lookup Tool
WHOIS Lookup is a free tool used to check domain registration details such as ownership, registrar, expiration date, and name servers.
Check domain availability, ownership, registration details, and expiry dates instantly.
What is WHOIS Lookup?
WHOIS is a public directory that stores domain registration data such as ownership, registrar, and key lifecycle dates. It is often used by domain investors, developers, security teams, and trademark owners to validate domain details quickly. For deeper network analysis, you can also use our DNS Lookup tool.
CuscusLab sends a direct query to authoritative WHOIS servers to fetch the latest available record, then displays the complete output for deeper review.
How to Use the WHOIS Lookup Tool
Enter a domain name such as example.com in the search box. You can paste a full URL and the tool will normalize it to the registered domain so the query reaches the correct registry source.
Press Search to run a live lookup. The results highlight registrar identity, registration and expiry dates, name servers, domain status codes, and any available registrant contact fields. When RDAP is available, structured data appears alongside the raw WHOIS response.
Use the raw output panels when you need the exact registry record for audits, trademark checks, or support tickets. The raw view is often required when comparing historical records or verifying changes from a registrar.
How to Read WHOIS Lookup Results Correctly
Registrar and dates
The registrar name and IANA ID show who manages the registration. Creation and expiry dates help you spot new domains, recent transfers, and upcoming renewals.
Domain status codes
Status values such as clientHold, transferProhibited, or redemptionPeriod explain why a domain might not resolve or transfer. Multiple statuses can appear, so read the most restrictive first.
Name servers and DNS
Name servers reveal the authoritative DNS provider. They are useful for diagnosing propagation issues and for confirming which platform controls the zone records.
Privacy and redaction
Many registries hide personal data. If privacy is enabled, contact fields may be blank or show a proxy service. In that case, reach the owner through the registrar or the listed abuse contact.
Information Provided
Registrar Info
Where the domain was registered (e.g., Namecheap, GoDaddy).
Important Dates
Creation, last update, and expiration timestamps.
Name Servers
DNS hosts responsible for directing domain traffic.
Domain Status
EPP status codes like clientHold or transferLock.
Registrant Contact
Owner details when publicly available.
Why Use This Tool?
Check Availability
See if a domain you want is already registered.
Verify Ownership
Confirm domain contact and registrar details.
Prevent Expiry
Track expiration dates before renewal is due.
Identify Scams
Review creation date and registrar history.
Contact Owners
Find publicly listed admin or abuse contacts.
Frequently Asked Questions
What is a WHOIS lookup?
A WHOIS lookup is a query protocol that allows you to access a database containing information about a registered domain name. It reveals details such as the domain owner (registrant), registrar, registration and expiration dates, and nameservers.
Is this WHOIS tool free?
Yes, our WHOIS lookup tool is 100% free to use. You can perform unlimited searches to check domain availability and ownership details without any cost or registration.
Why is some WHOIS information hidden?
Due to privacy regulations like GDPR, many domain owners use privacy protection services to redact their personal contact information (email, phone, address) from public WHOIS records. In these cases, you will see the privacy service provider's details instead.
How can I find out when a domain expires?
Simply enter the domain name into our WHOIS search bar. The results will display the "Registry Expiry Date" or "Registrar Registration Expiration Date," telling you exactly when the domain registration is set to expire.
Deep Dive: The Architecture of WHOIS and RDAP
The protocol known as WHOIS (defined in RFC 3912) has served as the backbone of domain data retrieval since the early 1980s. Originally designed as a directory for ARPANET users, it evolved into a mandatory system for the modern internet. However, traditional WHOIS suffers from several limitations, including a lack of standardization in output formats and no built-in support for internationalization.
To address these shortcomings, the Registration Data Access Protocol (RDAP) was developed. RDAP is the modern successor to WHOIS, providing structured data responses in JSON format. Unlike the legacy protocol, RDAP supports secure communication over HTTPS, tiered access levels (allowing registries to hide personal data while showing technical data to authorized parties), and better support for non-Latin character sets.
The Importance of WHOIS in Cybersecurity
For security researchers and threat hunters, a WHOIS record is often the first clue in investigating malicious activity. By examining a domain's registration history, security teams can perform Pivot Analysis. If a known phishing domain was registered using a specific email address or through a niche registrar, researchers can query those specific attributes to find other associated malicious domains before they are even used in an attack.
Furthermore, looking at the Creation Date is a critical step in identifying “Domain Tasting” or “Newly Registered Domains” (NRDs), which are frequently used in short-lived spam campaigns. Business Email Compromise (BEC) attackers often register domains that look visually similar to a legitimate company (typosquatting) and use them immediately; seeing a domain that was registered only 24 hours ago is a major red flag for any IT professional.
Understanding the Domain Expiration Lifecycle
A common misconception is that a domain immediately becomes available the moment it expires. In reality, ICANN-regulated domains (like .com, .net, and .org) follow a strict lifecycle designed to protect owners from accidental loss:
- Auto-Renew Grace Period: Lasts 0 to 45 days after expiry. The domain may stop resolving, but the owner can still renew at normal prices.
- Redemption Grace Period: Lasts 30 days. The registrar has deleted the domain, and the owner must pay a high restoration fee to get it back.
- Pending Delete: Lasts 5 days. The domain cannot be restored and is waiting to be purged from the registry for anyone to register on a first-come, first-served basis.