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What Is TLD Enumeration
TLD (Top-Level Domain) enumeration discovers all domain registrations associated with a base name across different top-level domains — checking whether example.com, example.net, example.org, example.io, example.co, and hundreds of other TLDs are registered and by whom. This technique is essential for brand protection, security assessment, and domain portfolio management.
With over 1,500 TLDs available (including gTLDs like .com, .org, .io and ccTLDs like .uk, .de, .jp), organizations cannot realistically register their brand across all of them. TLD enumeration identifies which variations are already registered, potentially by competitors, domain squatters, or threat actors preparing phishing campaigns.
TLD Categories
| Type | Examples | Count | Registration |
|---|---|---|---|
| Generic (gTLD) | .com, .net, .org, .info | ~1,200+ | Open to anyone |
| Country Code (ccTLD) | .uk, .de, .jp, .au, .ca | ~300+ | Some restricted to residents |
| Sponsored (sTLD) | .edu, .gov, .mil, .museum | ~15 | Restricted eligibility |
| New gTLD | .tech, .cloud, .security, .app | ~1,000+ | Open (most) |
| Infrastructure | .arpa | 1 | Technical use only |
Common Use Cases
- Brand protection: Discover unauthorized registrations of your brand name across TLDs before they are used for phishing, counterfeiting, or brand abuse
- Phishing detection: Identify domains registered with your brand name that could be used in phishing campaigns targeting your employees or customers
- Domain portfolio management: Audit which TLDs you own and identify gaps that should be defensively registered
- Competitive intelligence: Discover which TLDs competitors have registered and identify new product launches or geographic expansions signaled by domain registrations
- Merger/acquisition due diligence: Inventory all domain registrations associated with an acquisition target
Best Practices
- Prioritize high-risk TLDs — Not all TLDs are equal risk. Focus defensive registration on .com, .net, .org, your country's ccTLD, and industry-relevant TLDs (.io, .tech, .security).
- Monitor for new registrations — Set up domain monitoring alerts for your brand name across popular TLDs. Services like DomainTools and DNS Twist provide automated monitoring.
- Check look-alike variations — Beyond TLD enumeration, check for typosquatting (gogle.com), homograph attacks (using similar Unicode characters), and combosquatting (brand-security.com).
- Register defensively — Proactively register your brand on high-traffic TLDs and redirect them to your primary domain. This is cheaper than fighting domain squatters after the fact.
- Document and track — Maintain a centralized inventory of all domain registrations with renewal dates, registrars, and DNS configurations. Expired defensive domains are quickly snapped up by squatters.
References & Citations
- Internet Assigned Numbers Authority (IANA). (2024). Root Zone Database. Retrieved from https://www.iana.org/domains/root/db (accessed January 2025)
- ICANN. (2024). Uniform Domain-Name Dispute-Resolution Policy. Retrieved from https://www.icann.org/resources/pages/help/dndr/udrp-en (accessed January 2025)
- Wikipedia. (2024). Typosquatting. Retrieved from https://en.wikipedia.org/wiki/Typosquatting (accessed January 2025)
Note: These citations are provided for informational and educational purposes. Always verify information with the original sources and consult with qualified professionals for specific advice related to your situation.
Key Security Terms
Understand the essential concepts behind this tool
Frequently Asked Questions
Common questions about the TLD Enumerator
TLD enumeration checks domain availability across multiple top-level domains (TLDs). Example: checking example.com, example.net, example.org, example.io, etc. Used for: brand protection (register variants before squatters), typosquatting detection (find malicious lookalikes), reconnaissance (discover company assets), domain availability research. 1,500+ TLDs exist: generic (.com, .net), country-code (.uk, .de), new gTLDs (.app, .dev). Automates manual WHOIS checks.
ℹ️ Disclaimer
This tool is provided for informational and educational purposes only. All processing happens entirely in your browser - no data is sent to or stored on our servers. While we strive for accuracy, we make no warranties about the completeness or reliability of results. Use at your own discretion.