is a free online tool to find open ports in your system. This tool lets you scan open ports which may prove security holes to hackers. You can also test whether port forwarding is working or not.

FTP - 20 SSH - 22 SMTP - 25 HTTP - 80 IMAP - 993 RDP - 3389 POP3 - 110 Quick Scan[15 Port] Long Scan[36 Port]

    What is open port checker?

    An open port checker is a tool or utility used to determine which ports on a computer or network device are open and listening for connections. Ports are virtual points where network connections start and end.

    They are associated with an IP address of the host as well as the type of protocol used for communication. The most common protocols are TCP (Transmission Control Protocol) and UDP (User Datagram Protocol).

    When a port is open, it means that it is actively listening for incoming connections from other computers. This is necessary for various services and applications to function correctly, such as web servers (port 80 for HTTP, port 443 for HTTPS), email servers (port 25 for SMTP, port 110 for POP3, port 143 for IMAP), FTP servers (port 21), and many others.

    What are ports?

    ports allow software applications to share hardware resources without interfering with each other. Computers and routers automatically manage network traffic traveling via their virtual ports. There are 65,536 ports to choose from.

    Ports 0 to 1023 - Well known port numbers. Only special companies like: MS SQL services (1433), Mail services POP3(110), IMAP(143), SMTP(25), Web services HTML(80).

    Ports 1024 to 49151 - Registered ports; meaning they can be registered to specific protocols by software corporations.

    Ports 49152 to 65536 - Dynamic or private ports; meaning that they can be used by just about anybody.

    What is Port Forwarding?

    Port Forwarding is a special function on the router, allowing transfer of data packets from the outside (from the Internet) to devices or computers on your local network (LAN). Usually the port on your router will be closed to prevent hackers on your system. But when you use the service to connect through port on the router you need to open it. For example: Yahoo! Messenger you need one of the following ports must be open: 5061, 443, 80.

    Share it with friends

    Common ports

    FTP Control 21
    SSH 22
    Telnet 23
    SMTP 25
    DNS 53
    HTTP / Web 80
    POP3 110
    IMAP 143
    HTTPS 443
    IMAP SSL 993
    POP3 SSL 995
    MSSQL 1433
    REMOTE 3389
    VNC 5900