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TCP Port Check

Check whether a TCP port is open (host:port).

About the TCP Port Check tool

Check whether a TCP port is open (host:port).

Tip: from any lookup box on the site you can type tcp:example.com to run this tool directly.

Results are generated live. Each finding is graded as an error, warning or pass and explained so that you know what to fix and why it matters.

Monitor this automatically

Get alerted when this check starts failing, when you land on a blacklist or when a certificate or domain is about to expire.

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