Every subdomain you own, including the forgotten ones

Free tool, no signup and no daily limit, published by LANXAS, a French artificial intelligence company. Servers are located in France and no analysis data is retained.

Why it matters

• A staging subdomain left reachable can be indexed by Google and compete with you through duplicate content.
• A forgotten old service remains an entry point for an attacker, often unpatched for months.
• Every live subdomain is a distinct asset: it deserves its own sitemap, its own tags and links back to the main domain.
• A subdomain that no longer responds but whose DNS record still exists can be hijacked by a third party.

How discovery works

Since 2018, every certificate authority must publish each issued certificate into verifiable public logs, called certificate transparency logs. Those logs are freely readable by anyone.

One consequence is often overlooked: as soon as a subdomain gets a security certificate, its name becomes public and permanent, even if the service was never announced. A subdomain named staging or admin is therefore known to everyone. The practical conclusion is simple: never rely on the secrecy of a subdomain name as a security measure.

Frequently asked questions

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