Checking WHOIS is a standard step when buying a domain, researching competitors, or investigating abuse.
1. Command Line
whois example.com
whois example.com | grep -i "registrar\|expir\|name server"2. Online WHOIS Services
| Service | Features |
|---|---|
| lookup.icann.org | Official, all TLDs |
| who.is | Clean interface |
| DomainTools | WHOIS history, reverse lookup |
| SecurityTrails | Historical DNS data |
⚠️ History penalty: A domain may have been used for spam or link farms. It could carry Google penalties. Always check history before buying a used domain.
💡 Good used domain signs: 5+ years old, stable ownership, clean spam history, backlinks from authoritative sites.