Reverse DNS
Looks up the hostname (PTR record) associated with an IP address. Useful for verifying mail server identity, investigating an unfamiliar IP in your logs, or confirming that a hosting provider has set correct reverse DNS for your server.
How to run a lookup
- 1
Enter an IP address
Paste any IPv4 or IPv6 address into the input field — for example, 8.8.8.8 or 2001:4860:4860::8888.
- 2
Click Lookup
The tool performs a reverse DNS query and returns the PTR record value — the canonical hostname that the IP resolves to.
- 3
Read the result
If a PTR record exists, you'll see the associated hostname. If none is found, the IP has no reverse DNS configured.
Common use cases
Mail server verification — Many spam filters check that the sending IP's PTR record matches the HELO/EHLO hostname. Use this tool to confirm your mail server's reverse DNS is set correctly before going live.
Log investigation — An IP address appearing in your server access logs or firewall rules can be identified quickly by resolving it to a hostname.
Hosting confirmation — After requesting reverse DNS from your hosting provider, use this tool to verify the PTR record has been set.