Open Port Checker Online Tool

Domain or IP Address

Port Number

About Open Port Checker Online Tool:

The open port check tool can help you to find out whether a web server is open to external Internet on a specific port, or find out whether your server's port forwarding rules are setup correctly. List of some Well Known Ports:

Well Known PORT Number Description
21 FTP (File Transfer Protocol)
22 SSH (Secure Shell)
23 TELNET (Remote Login Service)
25 SMTP (Simple Mail Transfer Protocol)
53 DNS (Domain Name System)
80 HTTP (Hypertext Transfer Protocol)
110 POP3 (Post Office Protocol)
115 SFTP (Simple File Transfer Protocol)
443 TLS/SSL (Transport Layer Security)
3306 MySQL Database
8080 Apache Tomcat Web Server

comic port checker

More information about Port Checker:

Wikipedia (Port):

List of common port numbers:

Check Open Port with Python (with build-in package socket):

import socket

def port_checker(ip_address_or_domain, port_number):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        sock.connect((str(ip_address_or_domain), int(port_number)))
        return "PORT {0} is OPEN on '{1}'.".format(port_number, ip_address_or_domain)
    except Exception as e:
        return "PORT {0} is CLOSED on '{1}'.".format(port_number, ip_address_or_domain)

print(port_checker('', 443))

PORT 443 is OPEN on ''.

Check Open Port with Java (with build-in package


public class Port {
    public static boolean check_port(String ip_or_domain, int port) {
        try (Socket server = new Socket(ip_or_domain, port)) {
            System.out.println("Port " + port + " is OPEN on " + ip_or_domain);
            return true;
        } catch (IOException ignored) {
            System.out.println("Port " + port + " is CLOSED on " + ip_or_domain);
            return false;

    public static void main(String[] args) {
        boolean is_open = check_port("", 443);

Port 443 is OPEN on