01 · Enter the domain
Use a root domain, not a full URL. The server normalizes the input before querying public CT indexes.
PUBLIC SUBDOMAIN DISCOVERY
Find public subdomains without the mess.
Search Certificate Transparency records, combine multiple public sources, filter the results, and export a clean hostname inventory.
Subdomain Finder
Enter a root domain such as example.com
SCAN RESULTS
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0 unique subdomains · 0 results
Page 1 / 1
Simple, fast, readable.
Subdomain Finder is designed for passive public discovery. It does not pretend Certificate Transparency is a complete live inventory.
02 · Run the scan
Multiple independent CT providers are queried. One provider failing no longer prevents the other sources from returning results.
Recent scan history
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Common questions.
What is Subdomain Finder?
It collects public hostname records published through Certificate Transparency sources and filters them to the requested domain.
Is this a complete active scanner?
No. CT data can contain historical names and cannot guarantee that every hostname is currently live.
Why can a provider fail?
Public indexes can rate-limit, time out, or reject requests. The v46 engine isolates provider failures so one source does not block the others.
Can I export the results?
Yes. Results can be copied or exported as TXT, JSON, and CSV.