What is WHOIS: complete guide to domain verification
5 minute read · Updated June 5, 2026
WHOIS is a protocol for querying domain name registrar databases. It allows you to find out who registered a domain, when it was created, when it expires, which name servers are used, and the owner's contact information.
The word WHOIS literally means "who is". The protocol was created in 1982 and remains the primary way to get public information about a domain.
What can you find out through WHOIS?
When you enter a domain in our WHOIS checker, the following data is returned:
- Registrar — the company through which the domain was purchased (e.g., REG.RU, GoDaddy, Namecheap)
- Registration date — when the domain was first registered
- Expiration date — when it needs to be renewed (if missed — the domain is released)
- Last updated — when records were last changed
- Domain status — active, in transfer, in redemption period, etc.
- Name servers — which DNS servers serve the domain (pointing to hosting or DNS provider)
For IP addresses via IP WHOIS you can find out:
- Network block — which autonomous system (AS) the IP belongs to
- Provider — which operator allocated this address
- Region — where the network is registered
- Abuse contacts — who to contact with complaints about spam/attacks
Why check WHOIS
1. Before buying a domain
By checking someone else's site WHOIS, you can see what contact information the owner used, and whether it's worth registering a similar name in the same zone.
2. For security
If you received an email from example.com, checking WHOIS will show when it was registered. A site created 3 days ago is less trustworthy than one that's 10 years old.
3. For SEO competitor analysis
Check which competitors' domains are expiring soon — you might be able to grab a good name.
4. For spam or attack complaints
WHOIS shows abuse contacts for the network the attack is coming from. You can contact them officially.
5. Legal matters
Sometimes you need to identify the domain owner to resolve disputes, especially if a site violates rights.
GDPR and privacy
In 2018, GDPR came into force in the EU, and public WHOIS data began to be restricted:
- For .com, .net, .org — ICANN temporarily restricted public access to admin/tech/billing contacts, but registrar and dates remained open
- For .eu — EURid registry completely hides personal data
If WHOIS only shows registrar and dates but not the owner — that's normal, the data is protected by privacy law.
How to use our WHOIS
- Open the WHOIS page
- Enter a domain (e.g., google.com) or IP address (e.g., 8.8.8.8)
- Click "Check"
- In 1-2 seconds you'll get the full WHOIS response
- Click 🤖 "Explain" — our AI will analyze the response and highlight key facts
Common verification errors
Domain not found. Check the spelling, don't add www or http://. Just example.com, without prefixes.
Timeout. Some WHOIS servers (especially for .cn, .tk) respond slowly. Wait 10-15 seconds.
Incomplete response. For zones with restricted WHOIS (.eu) personal data is hidden by the registry.
WHOIS vs DNS - what is the difference
WHOIS and DNS are often confused. These are different things:
- WHOIS — who owns the domain (registration data)
- DNS — where the domain points (IP addresses, MX records, TXT)
Example: WHOIS google.com will show the domain is registered through MarkMonitor. DNS google.com will show it points to IP 142.250.190.78.
Security and restrictions
WHOIS servers work on TCP port 43. Many ISPs and corporate networks block outgoing connections on this port. Therefore:
- Our service makes requests on your behalf, bypassing your local restrictions
- Request limits: some registries (.com via Verisign) allow only 100 requests per minute from one IP — we cache responses
Related Tools
- Domain WHOIS — full domain info
- IP WHOIS — IP address info
- DNS Lookup — where the domain points
- SSL Check — HTTPS certificate
- Domain Age — domain age
FAQ
Is WHOIS legal?
Yes. WHOIS is an open public protocol, used by registrars, security researchers, and businesses. Querying WHOIS is completely legal.
Can I hide my data in WHOIS?
Yes. Most registrars offer WHOIS privacy protection (free at Cloudflare Registrar, $5-10/year at others). Your data is replaced with the privacy service's contacts.
What to do if my domain is registered under someone else's name?
Contact the registrar through which the domain was registered. If fraud is involved — file a UDRP complaint with ICANN arbitration.
Why does WHOIS sometimes return an empty response?
The WHOIS server for that zone may be down, or the domain doesn't exist. Try again in a few minutes.
WHOIS is a simple and reliable tool. With it you can quickly check a site's reputation, find abuse contacts, or simply find out a domain's age. Our service makes requests anonymously, caches responses, and adds AI explanation so you don't have to dig through raw data.