Single Port Checker

Checks if a specific TCP port is open and accessible (using a proxy).

Enter host and port to begin.
โš ๏ธ **CLIENT-SIDE LIMITATION:** This tool uses a public CORS proxy (`corsproxy.io`) to bypass browser security and check the port. It is NOT a full scanner and may only show **OPEN** status for common web ports (80/443).

How Port Checking Works Here

  1. Browser Limit: Standard browsers block direct connection attempts to arbitrary ports (security policy).
  2. Proxy Bypass: We send your request to an external CORS Proxy service. This proxy tries to connect to the target host and port.
  3. Status Interpretation: If the proxy successfully establishes a connection and gets an HTTP response (Status 200, 404, etc.), we report the port as **OPEN**.
  4. Timeout: If the connection is refused or times out (5 seconds), we report the port as **CLOSED**.

Why This is Useful

  • Firewall Testing: Quickly verify if your **web server ports (80, 443)** are accessible from the public internet after firewall changes.
  • Troubleshooting: Confirm if a specific service (like an API on port 8080) is responding.
  • Common Ports: You can test ports like 21 (FTP), 22 (SSH), 25 (SMTP), 80 (HTTP), 443 (HTTPS), 3306 (MySQL), 8080 (Proxy/Web).
  • Client-Side Security Check: Use it to understand browser security policies related to network access.