Subdomain Finder Professional

Professional subdomain discovery using open-source methods with export options.

SEO Guide for Subdomain Finder Professional This guide shows how to use the extension for SEO research, content governance, and technical audits. It focuses on lawful, passive discovery and safe validation. When to Use It - Site audits and migration prep - Detecting duplicate or thin content across subdomains - Mapping local or product subdomains - Monitoring brand and property sprawl Typical SEO Questions Answered - Which subdomains are live and should be indexed? - Are there forgotten hosts with legacy content? - Are staging or dev subdomains exposed to search? - Which hosts should be consolidated or redirected? 1. Start with passive sources only. 2. Export CSV and sort by subdomain pattern. 3. Validate DNS and HTTP to confirm live hosts. 4. Audit indexability and content quality per host. 5. Build a consolidation or redirect plan. - DNS OK + HTTP OK: likely active and reachable. - DNS OK + HTTP OPAQUE: reachable but response is blocked by browser policy. - DNS OK + HTTP empty: likely live but not responding on HTTPS. - DNS NO + HTTP empty: likely inactive or misconfigured. Export Formats CSV Columns - subdomain - dns - http - source