Reverse DNS Lookup

Find the hostname associated with any IP address using PTR records.

>_
Enter an IP address to find its hostname
Results will show the PTR record and associated hostname

What is Reverse DNS?

Reverse DNS (rDNS) is the process of resolving an IP address back to a hostname. While standard DNS maps domain names to IP addresses, reverse DNS does the opposite by looking up PTR (Pointer) records in the in-addr.arpa zone.

How It Works

To perform a reverse lookup, the IP address octets are reversed and appended with .in-addr.arpa. For example, looking up 8.8.8.8 queries the PTR record at:

8.8.8.8.in-addr.arpa. IN PTR dns.google.

Why PTR Records Matter

  • Email Deliverability — Many mail servers reject email from IPs without valid PTR records. A matching reverse DNS entry helps prove the server is legitimate.
  • Security and Logging — Reverse DNS helps identify the source of network connections in server logs and security audits.
  • Anti-Spam Checks — Spam filters often verify that the sending IP has a PTR record that resolves back to the same IP (forward-confirmed reverse DNS).
  • Network Troubleshooting — Reverse lookups help identify which servers or services are associated with specific IP addresses.

Who Sets PTR Records?

PTR records are managed by the owner of the IP address block, typically your hosting provider or ISP. You usually need to request PTR record changes through their control panel or support team.