Subdomains Finder.com

Discover subdomains, analyze IP infrastructure, and uncover security insights with precision.

Enter a root domain to discover all subdomains

Subdomain Discovery
IP & ASN Analysis
Port Detection
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Free Subdomain Finder — Discover Every Subdomain of Any Domain

SubDomains Finder is a free online subdomain finder and passive reconnaissance tool. Enter any root domain and our subdomain scanner instantly returns every known subdomain, its IP addresses, open ports, ASN provider, and hosting infrastructure — no installation, no API key, no command line required.

How the subdomain finder works

  1. Enter a root domain (e.g. example.com)
  2. We query Certificate Transparency logs, passive DNS databases, and public internet scan data
  3. Results are returned instantly — no active probes sent to the target

Who uses this subdomain scanner

  • Penetration testers during recon phase
  • Bug bounty hunters mapping attack surface
  • Blue teams auditing their own exposure
  • Sysadmins tracking shadow IT assets

What you get per subdomain

  • IPv4 / IPv6 addresses
  • Open ports and detected services
  • ASN & hosting provider
  • Country & CDN/WAF detection

Unlike CLI tools like Subfinder or Amass that require installation, SubDomainsFinder.com is a fully browser-based subdomain enumeration tool — paste a domain, get results in seconds. Compare all subdomain enumeration tools →