IP to Domain Lookup
Find domain names associated with IP addresses using reverse DNS PTR record lookups
Enter an IPv4 or IPv6 address to find reverse DNS (PTR) records. For example, 8.8.8.8. This can fail if the IP has no PTR—results may be empty.
Note: This shows PTR records only, not all domains that might resolve to the IP
About Reverse DNS (PTR) Lookup
⚠️ Important Limitation
This tool shows PTR records only - domains that the IP owner has configured to point back to this IP. It does NOT show all domains that might resolve to this IP address.
Reverse DNS (PTR records) is the opposite of regular DNS lookup. While regular DNS finds the IP address for a domain, reverse DNS finds the configured hostname for an IP address. Many IP addresses don't have PTR records configured.
PTR records are commonly used for email server verification, network diagnostics, and security purposes. Many mail servers require valid reverse DNS entries to accept emails.
Common use cases:
- Email server configuration and troubleshooting
- Network security and forensics investigations
- Identifying server hostnames from IP addresses
- Verifying domain ownership and configuration
- Network mapping and reconnaissance
- Analyzing shared hosting environments
Finding domains that point TO an IP:
- Certificate Transparency: Search crt.sh or censys.io for SSL certificates
- DNS Databases: Use SecurityTrails, PassiveTotal, or VirusTotal
- Web Crawlers: Check Shodan, ZoomEye, or similar services
- Historical Data: Use DNS history services to find past associations
- Subdomain Tools: Use subdomain enumeration tools for known domains
Why PTR records are limited:
- PTR records are optional and many IP owners don't configure them
- Shared hosting can have hundreds of domains on one IP without PTR records
- CDNs serve thousands of sites but may only have one PTR record
- Many websites use the same IP without reverse DNS configuration
Important limitations:
- PTR records are not mandatory and may not exist for all IP addresses
- Private network IPs (192.168.x.x, 10.x.x.x) typically don't have public PTR records
- Some hosting providers don't configure reverse DNS for shared hosting
- Corporate firewalls may block reverse DNS queries
- Results may vary depending on your DNS resolver
Try Similar Tools
Continue your workflow with these related developer tools
JSON Formatter
Format, validate, and minify JSON data with syntax highlighting
Try Now JSON FormatterJWT Decoder
Decode and verify JSON Web Tokens with header and payload inspection
Try Now JWT DecoderJWT Creator
Generate JSON Web Tokens with custom claims and signature
Try Now JWT CreatorReady to Get Started?
Explore our complete collection of 25+ developer tools. All privacy-first, no registration required.