Find Every Subdomain,Instantly

Run comprehensive subdomain enumeration with DNS, certificates, search engines, and passive sources. Built for security researchers, SEOs, and growth teams who need reliable recon at scale.

Free subdomain finder with comprehensive data sources
Enter a domain to find subdomains

What This Tool Does

Subdomain Finder enumerates all publicly visible subdomains for a given domain using passive sources (certificate transparency logs, search engines, DNS datasets) and optional active checks (DNS resolution, HTTP probing). The result is a deduplicated, validated list you can export for security testing, technical SEO, or asset inventory.

🔍 How Subdomain Enumeration Works

Passive enumeration: Certificate transparency (CT) logs, historical DNS, search engine footprints, public datasets.
Active validation: Resolves A/AAAA/CNAME, HTTP/HTTPS probe for status and title.
Normalization: Lower-casing, punycode handling, wildcard filtering, and root-domain grouping.

📊 Interpreting the Results

Domain: Discovered subdomain name
Title: HTML meta title from HTTP response
Discovered: First time we found this subdomain
Status: Live/down/timeout indicator
HTTP Code: Response status from our probe
Server: Web server type if detected
Response Time: Latency from our checks

Use Cases for Security, SEO, and Marketing

🛡️

Security & Pentest Recon

  • • Map attack surface comprehensively
  • • Prioritize high-value hosts for testing
  • • Watch for new exposures and risks
  • • Bug bounty subdomain discovery
📈

SEO & Marketing Audits

  • • Detect shadow microsites
  • • Find staging hosts affecting SEO
  • • Discover legacy subsites
  • • Monitor brand presence online
🏢

IT & Asset Inventory

  • • Maintain domain hygiene
  • • Lifecycle management
  • • Infrastructure mapping
  • • Compliance monitoring

Frequently Asked Questions

What is subdomain enumeration?

The process of discovering all subdomains associated with a root domain using passive and active techniques. Our tool combines certificate transparency logs, DNS records, and other public sources to find subdomains.

Is active probing safe?

We use standard DNS/HTTP requests with sensible rate limits. Our probes are non-intrusive and follow responsible disclosure practices. Always ensure you have permission to scan target domains.

Do you detect subdomain takeover risks?

We flag common patterns (e.g., CNAME pointing to deprovisioned services) that may indicate takeover risks. However, always verify findings manually before taking action.

What data sources do you use?

Our subdomain finder uses certificate transparency logs, DNS records, reverse DNS lookups, web crawl data, and partner data sources to provide comprehensive subdomain discovery.

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