Free · live registry data · no login
Reverse WHOIS (Domains by Owner or Email)
Find other domains registered with the same details.
How it works
Reverse WHOIS: find domains registered by the same owner (and its limits)
A true reverse WHOIS search lists every domain registered with a given name, company or email. That needs a commercial archive of hundreds of millions of records, which no free tool has and which GDPR redaction has largely emptied of personal data since 2018. We will not pretend otherwise. Enter one domain you know and we show what the live registry record does reveal about its owner, plus the free footprint signals (shared nameservers, mail setup, hosting) that link domains together, and where the real paid datasets live.
Results appear here after you click Show what is public.
How this works
- 1
Query the live record
We fetch the RDAP record for the domain you entered and show whatever registrant data the registry still publishes.
- 2
Check your search term
If you gave a name or email, we check whether it appears in that public record (it usually does not, because of redaction).
- 3
Map the footprint
Nameservers, MX, IP, SPF includes and verification TXT tokens are the public signals that can tie domains to one operator.
Frequently asked questions
- Is there a free reverse WHOIS lookup?
- Not a real one. Reverse WHOIS requires a historical database of all registration records, which only commercial providers (DomainTools, WhoisXML, Whoxy) maintain, and since GDPR most registrant data is redacted at the source. Free tools that claim otherwise usually show a handful of cached matches or nothing.
- How do I find all domains owned by a company?
- Start from a known domain and follow footprints: unique Google/Microsoft verification TXT tokens, bespoke nameservers, shared TLS certificates on crt.sh, Google Analytics IDs via BuiltWith, and reverse-IP lists. Company names (unlike personal names) are often still public on the record, so a paid reverse WHOIS by organisation can work.
- Can I find out who owns a domain by email address?
- Only through paid historical archives for records created before 2018, or if the domain has no privacy and the registry publishes contact data. For a legitimate legal interest, registrars are obliged to disclose redacted data on request; ICANN's Registration Data Request Service routes such requests.
- Why is this useful for brand protection?
- Finding the other domains behind a phishing or counterfeit site lets you report them together and spot the next one early. Footprint signals (same nameservers, same verification tokens, same IP) are what investigators use once the WHOIS record is redacted.
- Does WHOIS privacy hide me from reverse WHOIS?
- Yes, going forward. Privacy replaces your details with the proxy service's, so new reverse searches by your name find nothing. Records from before you enabled privacy may still exist in historical archives.
Every MailShrine domain includes WHOIS privacy, transfer lock, Anycast DNS with DNSSEC and two business mailboxes.