Reverse DNS Lookup (PTR)
Enter an IP address to find its PTR record and confirm that the hostname resolves back to the same address.
How it works
Normal DNS turns a name into an IP. Reverse DNS goes the other way, using PTR records stored under special names: an IPv4 address is reversed and placed under in-addr.arpa, and an IPv6 address is split into single digits, reversed and placed under ip6.arpa.
The PTR record is controlled by whoever owns the IP, usually your hosting provider, not by your domain's DNS. Mail receivers use it as a trust signal, and they look for forward-confirmed reverse DNS: the PTR hostname must resolve back to the same IP. This tool performs that second lookup for you.
| Result | Meaning |
|---|---|
| Forward-confirmed | The PTR name resolves to the same IP. Good. |
| Mismatch | The name resolves to a different IP. Mail may be rejected. |
| No PTR | No reverse record. Ask the IP owner to add one. |
Frequently asked
How do I set a PTR record for my server?
You cannot set it in your domain's DNS. Ask the company that gives you the IP address (your VPS or hosting provider), or set it in their control panel if they offer a reverse DNS field.
Why do mail servers care about PTR records?
Spammers often send from IPs with no reverse DNS or a generic name. Many receivers reject or down-rank mail from such addresses, so a matching PTR is a basic trust signal.
What should my PTR record say?
A hostname you control that points back to the same IP, ideally the name your mail server announces when it connects, such as mail.example.com.
Why does my IP show a name like ec2-1-2-3-4?
Cloud and consumer providers create automatic names from the IP. They are fine for general use, but for sending email you should ask for a custom one.
Why is there no result for a private IP?
Addresses such as 192.168.x.x or 10.x.x.x are not routed on the internet and have no public reverse DNS.