DNS & Network tools · FREE
From IP to hostname.
Enter an IP address to see the hostname (PTR record) it maps back to.
About this tool
Reverse DNS works the opposite of a normal lookup: it goes from an IP address to a hostname. A correct PTR record is especially critical for mail servers — many services flag or reject email whose sending IP has no valid PTR.
Frequently asked questions
What is reverse DNS?
A reverse lookup that resolves an IP back to a hostname, using the PTR record.
Why is PTR important for email?
Receiving servers often check sender legitimacy by matching PTR to hostname; missing it risks being marked spam.
Who sets the PTR record?
The owner of the IP block (usually the datacenter or server provider), not the domain owner.
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