Our free PTR record generator creates properly formatted reverse DNS records for both IPv4 and IPv6 addresses. Generate .in-addr.arpa notation for IPv4 or .ip6.arpa notation for IPv6 instantly, with support for single IP and batch processing. PTR (pointer) records are essential for email server validation, network troubleshooting, and security compliance. Most mail servers require valid reverse DNS to prevent spam. This tool automatically formats IP addresses into the correct reverse zone notation, handles the complex hexadecimal digit reversal for IPv6, and produces ready-to-deploy PTR record syntax for BIND and other RFC-compliant DNS servers. No registration required.
Batch processing advantage
Generate multiple PTR records at once (one per line). This is especially useful when setting up mail servers or documenting infrastructure across a subnet.
Generate Reverse DNS PTR Records
Create properly formatted PTR records for .in-addr.arpa (IPv4) and .ip6.arpa (IPv6) reverse DNS zones.
IP Version
Input Type
How to generate PTR records
- Select IP version: choose IPv4 or IPv6.
- Choose input type: Single IP or Batch Processing.
- Enter inputs: IP(s) and the hostname (FQDN) you want each IP to resolve to.
- Generate: click the button to get PTR record syntax.
- Copy & deploy: add the record(s) to your reverse DNS zone, or send them to your provider.
IPv4 vs IPv6 PTR record format
| Aspect | IPv4 (.in-addr.arpa) | IPv6 (.ip6.arpa) |
|---|---|---|
| Reversal unit | Octets (4 parts) | Hex digits (32 nibbles) |
| Example input | 192.0.2.1 | 2001:db8::1 |
| Example reverse name | 1.2.0.192.in-addr.arpa | ...8.b.d.0.1.0.0.2.ip6.arpa |
| Why use a generator | Fast & consistent formatting | Avoid manual expansion/reversal mistakes |
PTR record examples (plain text)
IPv4 example
Input: 203.0.113.10 → mail.example.com
Output: 10.113.0.203.in-addr.arpa. IN PTR mail.example.com.
IPv6 example
Input: 2001:db8::1 → mail.example.com
Output: 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.8.b.d.0.1.0.0.2.ip6.arpa. IN PTR mail.example.com.
Batch example
192.0.2.1 server1.example.com
192.0.2.2 server2.example.com
192.0.2.3 server3.example.com
Understanding PTR records & reverse DNS
PTR records enable reverse DNS: resolving an IP address back to a hostname. For strong email deliverability, aim for forward-confirmed reverse DNS (FCrDNS): the PTR points to a hostname, and that hostname’s A/AAAA record points back to the same IP.
How to set up PTR records
- For most VPS/cloud users: request PTR changes from your hosting provider (they control the reverse zone).
- If you manage reverse DNS yourself: add the generated PTR record lines to your reverse zone and reload your authoritative DNS server.
- Verify using Reverse DNS Lookup, and check forward DNS with DNS Records Lookup.
- For mail servers, validate end-to-end with Email Validator.
Common Questions
What is a PTR record?
PTR (Pointer) records are DNS records used for reverse DNS lookups. They map an IP address to a domain name (hostname), which is the opposite of what A or AAAA records do.
Why do I need PTR records?
PTR records are critical for email deliverability, because many receiving mail servers reject or spam-score messages from IPs without reverse DNS. They also help with troubleshooting and security by making logs human-readable (hostnames instead of raw IPs).
How do PTR records differ for IPv4 and IPv6?
IPv4 PTR records reverse the octets and append .in-addr.arpa (e.g., 192.0.2.1 → 1.2.0.192.in-addr.arpa). IPv6 PTR records expand the address, split it into hex digits, reverse them, and append .ip6.arpa—much longer and easy to get wrong manually.
Who controls PTR records?
PTR records are controlled by whoever owns the IP address range (usually your hosting provider or ISP). If you own an IP block and manage reverse zones, you can configure PTR records yourself.
How long does it take for PTR changes to propagate?
Propagation depends on TTL and caching. Changes may appear in minutes but can take up to 24–48 hours globally. Initial setup with a provider may take longer because it often requires a support request.
How can I verify my PTR records are working?
You can verify reverse DNS using dig -x, host, or nslookup, or use an online reverse DNS lookup tool. For best email results, verify forward-confirmed reverse DNS (FCrDNS) by checking that the hostname also resolves back to the same IP.
Related reverse DNS tools
- Reverse DNS Lookup — check existing PTR records
- DNS Zone Generator — build reverse zone files
- IP WHOIS Lookup — find IP ownership/network info