SubdomainsFinder.com

Enter a domain to uncover its subdomains, analyze their configuration, and enhance your security posture. All results are from passive sources; no active scans are performed.

Why SubdomainsFinder.com?

SubdomainsFinder.com is a free domain research and OSINT tool that uncovers hosts and subdomains related to any target domain. From an attacker’s perspective, identifying visible hosts is the first step in understanding a network’s exposure — and for defenders, it’s essential for building stronger security.

Attack

Quickly identify your attack surface with passive reconnaissance. Perfect for penetration testers, bug bounty hunters, and ethical hackers who need fast, accurate host discovery.

Defend

Empower your security team with actionable intelligence. Use passive DNS data for threat analysis, incident response, and cyber defense planning — all without sending a single packet to the target.

Learn

Master network-based OSINT and understand how adversaries think. Great for IT professionals, students, and security researchers.

Report bugs, issues, and exclusions at hi @ SubdomainsFinder.com.