Port Checker

About Port Checker

Test whether a TCP port is open on a target host. Useful for confirming firewall rules, NAT forwarding, and reachability of services like SSH (22), HTTP (80), MySQL (3306), Postgres (5432), etc. Connects from our server, not your browser, so it tests public reachability.

How to Use Port Checker

Quickly verify if a specific TCP port is open and accessible on a remote host or IP address.

1. 1

   Enter the target host address

   Type the domain name or public IP address of the server you wish to test into the host input field.

2. 2

   Specify the TCP port number

   Input the specific port number you want to check, such as 22 for SSH, 80 for HTTP, or 443 for HTTPS.

3. 3

   Initiate the port connectivity test

   Click the check button to trigger a connection attempt from our server to your specified target.

4. 4

   Analyze the reachability results

   Review the status output to see if the port is reported as open, closed, or filtered by a firewall.

5. 5

   Verify firewall and NAT rules

   Use the results to confirm that your port forwarding and security rules are correctly configured for public access.

Estimated time: PT1M

Frequently Asked Questions

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Port Checker Guide: Test Open TCP Ports and Firewalls

Learn how to use Port Checker to test TCP port reachability, verify firewall rules, and troubleshoot NAT forwarding for services like SSH, HTTP, and MySQL.