The Reverse IP Lookup Tool performs a reverse DNS (rDNS) lookup to find the hostname(s) associated with an IP address. While a standard DNS lookup maps a domain name to an IP, reverse DNS does the opposite — it maps an IP address back to a domain name.

How Reverse DNS Works

Reverse DNS uses PTR records (Pointer Records) stored in the special in-addr.arpa domain. For example, to look up 8.8.8.8, the query is made to 8.8.8.8.in-addr.arpa, which returns dns.google.

Who Controls PTR Records?

PTR records are managed by the owner of the IP address block — typically the ISP or hosting provider. Website owners cannot set PTR records for shared hosting IPs. This is why most residential IP addresses and CDN IPs may not have meaningful reverse DNS entries.

Common Use Cases

• Email verification: Mail servers check PTR records to fight spam.
• Network troubleshooting: Identify unknown hosts in network logs.
• Security auditing: Verify that a server's forward and reverse DNS match.
• Server identification: Find the hostname behind a cloud or CDN IP.