What is WHOIS Lookup?
WHOIS is a widely used internet record listing that identifies who owns a domain and their contact information. When you perform a WHOIS lookup, you can learn when a domain was registered, its expiration date, and details about the registrar and the registrant.
WHOIS data helps security professionals investigate suspicious domains, helps enforce intellectual property rights, and aids in resolving domain disputes. It can also be valuable for marketers researching business competitors or understanding ownership trends.
While WHOIS data is public, many domain owners use privacy protection services to mask personal contact details, providing proxy information instead. However, registrars are still required to keep real ownership records for compliance purposes.
For IP addresses, WHOIS lookups reveal which organization or ISP owns a particular block, offering insights into network structures and aiding in abuse mitigation and network troubleshooting.
New privacy regulations like GDPR have impacted the visibility of WHOIS records, leading to redacted or masked data in many regions. Understanding how to interpret WHOIS responses remains a crucial skill for cybersecurity and internet governance professionals.