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Subdomain Enumerator Online Free

Find active subdomains for any public domain. Scan common host prefixes using secure DNS queries to map domain structures and identify exposed web assets.

✓ Free security tool✓ No signup required✓ Fast results✓ Browser-based utility✓ Mobile friendly
🔒Privacy Note: This tool may contact external data sources or the domain, IP or URL you enter to complete the requested check.
⚠️Authorization Note: Use this tool only for domains you own, manage or have permission to analyze. Automated scans must comply with target safety rules.
Security Tools
Subdomain Enumerator
🌿

Subdomain Enumerator

Find common subdomains for a domain you own or have permission to analyze.

Domain
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Instructions

How to Use This Tool

1

Enter Domain

Type the target apex domain name (e.g. company.com) in the enumerator search field.

2

Launch Enumeration

Click the scan button to query common prefixes.

3

Verify DNS Resolution

Check which subdomains successfully resolve to active IP addresses.

4

Inspect Exposed Services

Identify staging, development, or admin endpoints that should be restricted.

Example

Auditing a corporate domain for forgotten staging sites

You want to ensure that old development environments are not publicly accessible. Input your domain. The enumerator checks prefix records and discovers 'dev.yourdomain.com' and 'stage.yourdomain.com' resolving to active IP addresses, reminding you to update access control rules.

Applications

Common Use Cases

Attack Surface Mapping

Discover active subdomains to evaluate security postures and close entry vectors.

Shadow IT Detection

Find subdomains created by teams outside standard IT registration channels.

DevOps Cleanup

Verify and clean up old DNS records for services that have been decommissioned.

Asset Discovery Studies

Learn about DNS records (A, CNAME), zone mapping, and subdomain structures.

Related Utilities

Related Security Tools

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Lookup domain SPF and security records.

WHOIS Domain Lookup

Check ownership registry registration data.

SSL Certificate Checker

Inspect website SSL and chain status.

Port Scanner

Verify open host TCP ports.

Questions

Frequently Asked Questions

How does subdomain enumeration work here?
The tool checks common host prefixes (like 'api', 'dev', 'mail', 'vpn', 'stage') and queries public DNS servers to verify which names resolve to active IP addresses.
Why is subdomain discovery important for security?
It helps map a domain's attack surface, exposing forgotten dev sites, legacy staging environments, or shadow IT assets that might contain unpatched software.
Is it safe and authorized to scan any domain?
No. Use this tool only for domains you own, manage, or have explicit permission to analyze. Unapproved scanning of target domains may trigger security alerts.
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