Reverse IP Lookup – Find Domain Name From IP
Free reverse IP lookup. Enter an IP address to find its hostname (PTR record) and identify the server or network behind it. Fast, accurate and no sign-up.
Reverse IP Lookup – Free Online Tool
Have an IP address and want to know what is behind it? Our free Reverse IP Lookup tool resolves an IPv4 or IPv6 address to its hostname using the PTR (pointer) record, helping you identify servers, mail hosts and network providers in seconds.
What is Reverse IP Lookup?
A normal DNS lookup turns a domain name into an IP address. A reverse IP lookup does the opposite: it asks DNS which hostname is assigned to a given IP. This mapping is stored in a special PTR record managed by whoever owns the IP block — usually a hosting company or internet provider.
Reverse DNS is widely used by mail servers to judge whether incoming email is trustworthy, and by system administrators to recognise traffic in their logs.
How to use the Reverse IP Lookup
- Enter the IPv4 or IPv6 address you want to investigate.
- Click submit to query the PTR record.
- Read the returned hostname, which often reveals the hosting provider or server name.
- Use the hostname for further checks such as a DNS or WHOIS lookup.
Key features
- Supports both IPv4 and IPv6 addresses
- Instant PTR record results
- No limits for normal use and no account needed
Common use cases
- Identifying unknown IP addresses in server or analytics logs
- Checking that your mail server has a valid PTR record to improve email deliverability
- Finding which hosting company operates a server
- Investigating suspicious traffic or login attempts
Frequently asked questions
Why does an IP return no hostname?
Not every IP has a PTR record. The owner of the IP range must create it, and many residential or cloud IPs are left without one.
Does reverse DNS matter for email?
Yes. Many mail servers reject or spam-filter messages from IPs without a matching PTR record, so mail servers should always have one.
Can I find all websites hosted on one IP?
A PTR record shows only the hostname assigned to the IP, not every site hosted there. Shared servers can host hundreds of domains on a single IP.
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