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Reverse WHOIS Lookup
Find all domains registered by a specific person, company, email address, or organisation. Discover hidden domain portfolios, track registrant ownership, and uncover related websites instantly.
Search Type
Enter Registrant Name or Company
Examples: Google LLC,
Elon Musk,
admin@example.com
Searching domain registrations…
Querying RDAP & WHOIS databases
0 domains
No Domains Found
No domain registrations were found matching this query. Try a different name, email, or keyword.
What is Reverse WHOIS Lookup?
A Reverse WHOIS Lookup is the inverse of a standard WHOIS query. While a regular WHOIS lookup retrieves registration information for a specific domain, a Reverse WHOIS search lets you find all domains associated with a particular registrant — whether identified by name, email address, organisation, phone number, or keyword.
This powerful technique is widely used by cybersecurity researchers, brand protection teams, domain investors, and digital forensics investigators to map out domain portfolios, uncover hidden ownership networks, and detect malicious infrastructure linked to known threat actors.
Standard WHOIS vs Reverse WHOIS
| Feature | Standard WHOIS | Reverse WHOIS |
|---|---|---|
| Input | Domain name (e.g. example.com) | Registrant detail (name, email, org) |
| Output | Owner info for that domain | All domains owned by that registrant |
| Best For | Checking who owns one domain | Discovering a domain portfolio |
| Use Case | Domain availability, expiry check | Brand protection, threat intelligence |
| Result Count | Single domain record | Can return hundreds of domains |
Common Use Cases for Reverse WHOIS
- Brand Protection: Find all domains registered using your brand name, company name, or executive names to catch cybersquatters early
- Cybersecurity & Threat Intelligence: Map out the infrastructure of phishing campaigns, malware authors, or scam networks by tracing related domains
- Domain Investment Research: Identify prolific domain investors and study their acquisition strategies and portfolio themes
- Competitor Analysis: Discover all web properties owned by a competitor organisation to understand their online footprint
- Due Diligence: Verify domain ownership claims during business acquisitions, mergers, or intellectual property disputes
- Legal Investigations: Support trademark infringement, copyright, or cybercrime cases by establishing domain ownership patterns
- OSINT Research: Open-source intelligence gathering to connect individuals, organisations, or entities across multiple domains
- Affiliate & Network Discovery: Identify website networks running under the same ownership for partnership or compliance purposes
Understanding WHOIS Privacy & Data Limitations
It is important to understand that Reverse WHOIS results may be incomplete due to several factors:
- GDPR & Privacy Laws: Since 2018, ICANN's GDPR compliance requirements mean most registrars now redact personal contact information from public WHOIS records by default, replacing it with privacy-proxy contact details
- Privacy Protection Services: Domain owners actively using services like Domains By Proxy, WhoisGuard, or PrivacyProtect.org have their real details hidden behind a generic registrar contact
- Historical vs Current Data: Data availability depends on when the domain was registered and whether privacy protection was applied retroactively
- ccTLD Restrictions: Country-code TLDs like
.uk,.de, or.inhave their own WHOIS policies and may restrict or omit registrant data entirely
For comprehensive, historical Reverse WHOIS data with full registrant details, commercial services such as DomainTools, WhoisXML API, or ViewDNS.info provide paid databases that aggregate historical WHOIS records before GDPR redaction.
How Our Reverse WHOIS Tool Works
Our free Reverse WHOIS tool queries the RDAP (Registration Data Access Protocol) — the modern successor to the legacy WHOIS protocol, standardised by ICANN. Here is the process:
- Step 1 — Input Parsing: Your search term is sanitised and classified by type (name, email, organisation, or keyword)
- Step 2 — RDAP Bootstrap Query: The tool queries IANA's RDAP bootstrap registry to identify which RDAP server handles the relevant TLDs
- Step 3 — Entity Search: An entity-level search is performed across RDAP endpoints to match registrant details against your query
- Step 4 — Domain Aggregation: Matching domains from the entity records are collected, deduplicated, and returned with available metadata such as registration dates and status
- Step 5 — Presentation: Results are displayed as a sortable, copyable domain list with direct links to full WHOIS records for each domain
Frequently Asked Questions
Yes. Reverse WHOIS lookup is entirely legal. It queries publicly available registration data from ICANN-accredited databases. The information is the same data domain registrants consent to publish upon registration. It is used legitimately by security researchers, legal professionals, brand protection services, and domain investors worldwide.
Most likely due to GDPR privacy protection. Since 2018, the majority of registrars redact registrant contact details (name, email, address) from public WHOIS/RDAP records, replacing them with generic proxy contact information. This makes it impossible to search by the real registrant's details publicly. For comprehensive historical data, commercial Reverse WHOIS services maintain pre-GDPR archives.
Email address searches historically yield the most precise results because email addresses are unique identifiers. However, due to GDPR redaction, older domains (pre-2018) or those registered without privacy protection are most likely to return matches. Company names registered in US, Australia, or Asian registrars often have fewer redaction requirements and may return better results.
Not through public WHOIS/RDAP. Privacy-protected domains display the proxy service's contact details rather than the actual owner's. To identify domains hidden behind privacy services, you would need either a court order to compel the registrar to reveal the true registrant, or a commercial service that may have captured the data before privacy protection was applied.
A standard WHOIS lookup takes one domain as input and returns the owner's details. Reverse WHOIS does the opposite — it takes an owner's identifier (name, email, or company) as input and returns a list of all domains they have registered. Think of it as searching the WHOIS database from the registrant side rather than the domain side.
Yes, this Reverse WHOIS tool is 100% free with no registration, account creation, or API key required. It queries publicly available RDAP endpoints in real time. For bulk lookups, historical records, or comprehensive coverage including pre-GDPR data, commercial services like DomainTools or WhoisXML API offer paid plans.