Domain Tools
IP to Domain Lookup
Find the domain name associated with an IP address, where publicly available.
Enter an IP address to find its associated domain name, where publicly available via reverse DNS.
Enter an IP address (or a domain, to look up its IP first).
JustChecker tracks your server's IP address and alerts you if it ever changes.
Frequently Asked Questions
Not every IP address has a reverse DNS (PTR) record configured, and shared hosting environments in particular often serve many different domains from one IP with no single "the" domain associated with it in reverse DNS.
It returns whatever the reverse DNS (PTR) record for that IP is configured to point to - which may be just one of several domains actually hosted there, or a generic hosting-provider hostname rather than any specific customer domain.
No - reverse DNS returns at most one hostname per IP by design; discovering every domain sharing an IP typically requires different techniques (like reverse IP/hosting lookups), which this specific tool doesn't perform.
Common uses include investigating the source of suspicious traffic in server logs, verifying infrastructure ownership, or basic network diagnostics when only an IP address is known.
The resulting hostname often hints at the hosting provider or organization (e.g. a cloud provider's naming pattern), though for a precise ownership answer a dedicated IP allocation/WHOIS lookup for that IP range is more authoritative.
Yes - reverse DNS lookups are supported for both address families, following the same underlying PTR record mechanism regardless of whether the address is IPv4 or IPv6.