PTR Record Checker
Reverse-DNS lookup for an IPv4 address.
Enter an IPv4 address to look up its PTR record, the reverse DNS that maps an IP back to a hostname. We query the live record straight from DNS over an encrypted connection. Nothing is stored.
This tool performs a reverse-DNS lookup for an IPv4 address: it queries the in-addr.arpa zone to find the PTR (pointer) record that maps that IP back to a hostname. Where an A record turns a name into an address, a PTR record does the opposite, turning an address into a name. For example, the address 192.0.2.25 is looked up as 25.2.0.192.in-addr.arpa, with the octets reversed. The result is the hostname the IP's operator has published for it.
Why PTR records matter for email
Almost every receiving mail server checks the PTR record of a connecting IP before accepting mail. A sending IP with no PTR record, or a generic-looking one such as a raw ISP-assigned name, is widely treated as a sign of spam and is frequently rejected or heavily filtered. A clean, meaningful PTR that matches your sending domain is one of the baseline expectations for good deliverability, alongside SPF, DKIM and DMARC.
How to read and fix the result
If the tool returns a hostname, a PTR record exists; if it returns nothing, the IP has no reverse DNS and you should arrange one. Crucially, only the owner of the IP address block can set a PTR record, which usually means your hosting provider, ISP or cloud platform rather than your own DNS. Raise a request with them to point the PTR at a hostname you control, then confirm that hostname also resolves forward to the same IP so it passes forward-confirmed reverse DNS. Reverse DNS is just one signal; if you want the full sending posture handled for you, our done-for-you service manages authentication end to end. See the wider requirements for context.
Frequently asked questions
What is a PTR record?
A PTR (pointer) record maps an IP address back to a hostname, the reverse of an A record. It lives in the in-addr.arpa zone for IPv4, with the address octets written in reverse order, so 203.0.113.5 is queried as 5.113.0.203.in-addr.arpa.
Why does my IP have no PTR record?
Reverse DNS is controlled by whoever owns the IP block, not by your domain's DNS. If no record appears, your hosting provider, ISP or cloud platform has not delegated or published one for that address, and you need to ask them to set it.
How do I set or change a PTR record?
You cannot set it in your own zone file. Open a request with the operator of the IP address (your provider) asking them to point the PTR at the hostname you want. Some clouds expose this in their console, others require a support ticket.
Does a missing PTR record stop my email from being delivered?
It often does. Many receiving servers reject or aggressively filter mail from IPs with no reverse DNS or a generic provider-assigned name. A meaningful PTR that matches your sending hostname is treated as a basic sign of a legitimate mail server.
What is the difference between a PTR check and an FCrDNS check?
A PTR check only confirms that the IP resolves to a hostname. An FCrDNS check goes further and confirms that the hostname also resolves forward back to the same IP, which is what mail servers actually test.