---
title: "What is Reverse DNS (pointer (PTR) record)?"
url: "https://lookvalid.com/glossary/reverse-dns.md"
canonical_url: "https://lookvalid.com/glossary/reverse-dns"
last_updated: "2026-10-18"
type: "conceptual"
summary: "Reverse DNS maps an IP address back to a hostname, using a PTR record, the opposite direction of an ordinary DNS lookup."
related: ["https://lookvalid.com/glossary/asn.md", "https://lookvalid.com/glossary/cidr.md", "https://lookvalid.com/glossary/spf.md", "https://lookvalid.com/products/ip.md"]
---

# What is Reverse DNS (pointer (PTR) record)?

Reverse DNS maps an IP address back to a hostname, using a PTR record, the opposite direction of an ordinary DNS lookup.

The owner of an address block controls its reverse records. Mail servers commonly check that a sending address has a sensible reverse name, and that the name resolves back to the same address.

A hostname such as one that names a cloud provider or a home internet service gives another clue about what sits behind an IP address.

## Related

- [What is ASN (Autonomous System Number)?](https://lookvalid.com/glossary/asn.md)
- [What is CIDR (Classless Inter-Domain Routing)?](https://lookvalid.com/glossary/cidr.md)
- [What is SPF (Sender Policy Framework)?](https://lookvalid.com/glossary/spf.md)
- [IP Intelligence API](https://lookvalid.com/products/ip.md)