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Open Port Checker

Check whether a public TCP service is reachable from the WebToolsPlanet server.

TCP CheckPublic Hosts OnlyRate LimitedNo Signup

Last updated: May 29, 2026

The host and port you enter are sent to our server, which resolves the hostname and attempts a direct TCP connection to check whether the port responds. Your query itself is not written to a database — only a temporary, in-memory rate-limit counter is kept, which clears automatically.
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What is Open Port Checker?

Open Port Checker attempts a short TCP connection to a public hostname or IP address and port. It reports whether the connection opened, was refused, or timed out. This helps verify whether a web server, mail server, SSH endpoint, database listener, or custom TCP service is reachable from the public internet.

How to Use Open Port Checker

1

Enter a public hostname or IP address.

2

Enter the TCP port number, such as 80, 443, 22, or 25.

3

Click Check Port.

4

Review the status, checked address, latency, and resolved addresses.

5

Copy or download the report.

Common Use Cases

  • Checking whether HTTPS port 443 is reachable after a firewall change.
  • Testing whether an SMTP, SSH, or custom TCP service is exposed publicly.
  • Confirming a cloud security group or hosting firewall allows a port.
  • Distinguishing a refused connection from a timed-out filtered port.
  • Documenting public service reachability during deployment checks.

Example Input and Output

Checking whether HTTPS is reachable on a public host.

Host and port
Host: example.com
Port: 443
Port status
Status: open
Message: TCP connection opened successfully.

How This Tool Works

The server validates the host and port, resolves the hostname, rejects private or reserved addresses, then opens one TCP socket with a short timeout. It returns open, closed, or filtered based on the connection result.

Technical Stack

TCP socketsDNS resolutionSSRF target blockingRate limiting

Safety Limits

The checker runs server-side, validates public targets, blocks local and private ranges, resolves hostnames before connecting, and applies a short timeout and rate limit.

Frequently Asked Questions

What does open mean?

Open means the server accepted a TCP connection on that port from the checker. It does not verify the application protocol after the connection opens.

What does closed mean?

Closed usually means the host actively refused the TCP connection. The host was reachable, but no service accepted the connection on that port.

What does filtered mean?

Filtered means the connection timed out or could not complete. A firewall, routing policy, or network ACL may be dropping packets.

Can I check localhost or private IP addresses?

No. Private, local, reserved, and multicast targets are blocked to reduce SSRF and internal network scanning risk.

Can this scan many ports at once?

No. This tool checks one host and one port at a time and is rate limited. It is for focused diagnostics, not bulk scanning.

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