Reverse DNS (PTR) lookup

A reverse DNS lookup turns an IP address back into the hostname its owner has assigned to it (the PTR record).

How to use the reverse dns (ptr) lookup

  1. Enter an IP address.
  2. Press Look up.
  3. Read the PTR hostname the IP's owner has assigned, if any.

What reverse DNS tells you

Normal DNS turns a hostname into an IP; reverse DNS does the opposite, looking up the PTR record the IP's owner has set. Mail servers use it to gauge whether a sender is legitimate. Many residential and some hosting IPs have no PTR configured — that's normal, not an error. To go the other direction, use the DNS lookup tool.

Code & API examples

Use this from the command line or your code. The API is free, GET-only, and returns JSON.

API (curl)
curl "https://vpn.golf/api/tools/reverse-dns?ip=8.8.8.8"
Shell (dig)
dig -x 8.8.8.8 +short

See all endpoints at /api/tools/.

Frequently asked questions

Normal DNS turns a hostname into an IP. Reverse DNS does the opposite — it looks up the PTR record an IP's owner has set, often used by mail servers to check legitimacy.

PTR records are optional and set by whoever controls the IP block. Many residential and some hosting IPs simply don't have one configured.
Related tools
IP address lookup DNS lookup tool What is my IP address?
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