Open Port Checker
Check whether a public TCP service is reachable from the WebToolsPlanet server.
Last updated: May 29, 2026
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Buy me a coffeeWhat 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
Enter a public hostname or IP address.
Enter the TCP port number, such as 80, 443, 22, or 25.
Click Check Port.
Review the status, checked address, latency, and resolved addresses.
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: example.com
Port: 443Status: 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
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.