Reverse DNS Lookup

From an address back to a name

Enter a single IPv4 or IPv6 address. The tool creates an in-addr.arpa owner for IPv4 or a nibble-reversed ip6.arpa owner for IPv6, then asks the selected resolver for PTR records.

IPv6 addresses are expanded before their hexadecimal nibbles are reversed. The result displays every PTR answer returned by the resolver, not just one preferred hostname.

192.0.2.10 → 10.2.0.192.in-addr.arpa
2001:db8::1 → nibble-reversed name under ip6.arpa

DOCUMENTATION EXAMPLE — not a live DNS response

What a PTR answer establishes

A PTR is reverse DNS data normally controlled by the network operating the address space. It does not prove that every hostname points back to that IP or that the host is safe.

Multiple PTR records are possible. A missing PTR does not establish that the address is unreachable, malicious or unused. Forward-confirmed reverse DNS would require additional checks and is not asserted here.

Not a list of websites on an IP

Reverse DNS lookup is not reverse-IP enumeration. Shared hosting can serve many domains while publishing no corresponding PTR list. This tool does not crawl websites, use a private database or claim to identify every domain sharing an address.

IPv6 scope identifiers such as %eth0 are interface-specific and are rejected. A public resolver cannot inspect a device’s private local naming configuration.

Changing reverse DNS

If a PTR value needs updating, contact the address-space provider or use its delegated reverse-zone controls. Editing the forward A record in a domain’s DNS panel does not automatically change the PTR.

Mail operators may inspect reverse DNS as one signal among many. A PTR record alone is not a promise of email acceptance.