Reverse DNS Lookup - Find Hostname from IP Address
Look up the hostname associated with any IP address using reverse DNS. Verify PTR records and identify servers by their IP addresses instantly.
Understanding This Tool
What It Does
Look up the hostname published for an IP address, then check whether that hostname resolves back to the same address. The lookup queries the reverse zone directly, so it also reports how long the answer is cached and which nameservers are delegated to answer for the surrounding address block.
Understanding the Results
- Hostname (PTR): The name published in the address's reverse zone, or a note that no record exists
- Forward-confirmed: Whether that hostname's A or AAAA record points back to the IP you looked up. A mismatch means the two directions disagree
- PTR record TTL: How long resolvers keep the answer before asking again, in seconds
- Reverse zone: The in-addr.arpa or ip6.arpa name the query was sent to
- Authoritative nameservers: The servers the parent block delegates the reverse zone to
Common Use Cases
- Server Identification: Put a name to an address in a log file or firewall rule
- Mail Server Setup: Confirm a sending IP has a PTR record that forward-confirms, which most inbox providers require
- Deliverability Debugging: Spot the mismatch behind a rejection that cites reverse DNS
- Network Forensics: Map infrastructure during an investigation
- Delegation Checks: Find out which nameservers your provider expects to hold your PTR records
Pro Tips & Best Practices
- Forward Confirmation Matters: A PTR record on its own is not enough. Mail filters want the hostname to resolve back to the sending IP
- Not Every IP Has One: Residential and cloud addresses often ship without a PTR record
- Only the Block Owner Can Set It: PTR records live in the ISP's or hosting provider's zone, so ask them rather than editing your own DNS
- Watch the TTL: A long TTL means a freshly added record can take hours to appear everywhere
Frequently Asked Questions
What is reverse DNS?
Why is reverse DNS important?
What if an IP has no reverse DNS?
Can I set my own reverse DNS?
Should reverse DNS match forward DNS?
How long is a reverse DNS answer cached?
How this tool works: This tool runs in your browser and on our server in real time. Depending on the tool, results are computed directly from the input you provide or retrieved from live, authoritative data sources at the moment you run a lookup. We do not sell your data, and your lookups are kept private — any history shown here is stored only on your device.