Subdomain Finder
Discover active subdomains of a domain by checking common prefixes via DNS and querying certificate transparency logs.
Examples
Subdomain Finder Tool
Discover active subdomains of a domain by checking common prefixes via DNS and querying certificate transparency logs.
What Subdomain Finder Does
- Common Subdomain Check: Tests ~30 common subdomain prefixes (www, mail, api, dev, staging, etc.) via DNS lookup
- Certificate Transparency: Queries crt.sh certificate logs to find additional subdomains
- DNS Validation: Only reports subdomains that resolve to a real IP address
- IP Resolution: Shows the resolved IP address for each discovered subdomain
- Active Status: Confirms each subdomain is currently active via DNS A record
Why Use Subdomain Finder?
This tool checks ~30 common subdomain prefixes via DNS A record lookups and supplements results with certificate transparency data from crt.sh. It only reports subdomains that are currently active. It does not perform brute-force enumeration or guarantee complete coverage.