How To Check Open Ports In Windows

To know which port is open in window can be done easily. So you can check open port in windows by doing this. All you need is a program that displaces all TCP and UDP connections and their respective states.

And all windows computers have such program—Netstat. Even when you do not supply, it does it by default. The only exceptions are ports in listening mode (you can also use it to know the port that are in listening mode too)

Using Netstat on the server itself to check for open ports in windows

So, a program can open a port and there is no client connected to it. And Netstat can also help you figure out which port are in listening mode—like I have said earlier. How it does that? Simple.

Common port numbers are translated into the protocol usually associated with them by Netstat. For instance it converts IP addresses to their DNS names and also it translated port 25 to smtp.

You may want to see the port or IP address numbers. If you want to do that, you should use n-switch. The process identifier (PID) or even the executable will not be identified. It is Netstat default setting.

On the other hand, you can see the service within the executable that opened the port by using the b-switch. When you use it that is what it tells Netstat to do.

And there is the o-switch which you can use to show the same PID for a process. You should know that Task Manager does the same thing too.

Using Telnet from outside to check open ports in windows

You should know too that telnet is not a default option in window Vista or 7 and so it is not recognized as an external command or internal for that matter. It is also not recognized as an operable program or batch file too.

But here is what to do: Go to ‘Start’ on your windows, click it and go to’ Control Panel’. It will display options.
Click on ‘Programs’ (it is usually below in the option displayed). And you should locate ‘Turn Windows Features on or off’. Click it and wait for it to load. You will see this at the top; ‘’ To turn a feature on, select its box. To turn it off, clear its check box. A filled box means that only part of the feature is turned on’’.

In the displayed list below, scroll down and select ‘Telnet Client’. And then click ‘Ok’. That is it.

And that is how you check for open ports from within or from outside in windows. Pretty straight forward, right? It sure is.

How to check if port is open on windows

The knowledge of how to check for open ports is important especially when you own a windows device. Here is an article about how to check if port is open on the windows operating system.

This can be done using any of the available port checker tools online. There are freeware tools for Microsoft Windows which can be used to check if a port is open.

These free utilities are quite effective at scanning for open ports.

How to Check For Open Ports in Windows

When troubleshooting network connectivity issues, there are ways to check for open (or listening) ports. In this article, we will look at the port check tools available in order of their popularity.

1. NetStat.exe

The netstat.exe is a popular Windows command line located in the Windows ‘System32’ folder. It is very effective for checking for open ports or if a port is in use by a particular host.

The netstat command line to be used in checking for open ports in a local host should be entered in the command prompt (cmd.exe) as follows:

This displays the results across four columns with protocol type, IP address, foreign address and the state as the headings respectively.

The column of significant interest is the content of the second column in the command prompt display.

The “o” parameter can be added to the netstat command to show the application process ID (PID). A process ID column appears in the result as a fifth column.

Open Tasklist.exe to help identify the application using the open (listening) port from the command prompt.

2. TCPView.exe

The second on our list is TCPView.exe which is similar to the netstat.exe command. The difference between the two methods of checking for open ports is that TCPView.exe gives a detailed representation in a graphical format or graphical user interface (GUI).

By opting to use TCPView, you get to scan for which ports are open.

Also, as its extended benefit, it enables you to check both the local and remote TCP connection, the protocols that are being used as well as the processes involved.

TCPView can be downloaded from Microsoft SysInternals website and runs as a standalone application without any need to install.

3. PortQry.exe

An alternative method to check for open (listening) ports is the PortQry.exe Windows command.

It can be downloaded by visiting Microsoft Download’s Center and just like the TCPView command; it also runs as a standalone application.

The use of the PortQry.exe command line allows checking for open ports available on the local or remote host.

It works by downloading and extracting the executable file from the Download’s Center and opening a command prompt.

On the command prompt, enter portqry.exe and the parameter identifying the folder which contains the executable file.

It should be noted that the results obtained from running the portqry.exe are similar to that of the netstat.exe command except that it also shows the port statistics stating the number of port mappings and ports in each state.

4. OpenPortViewer.exe

Open Port Viewer is our home develop a free tool design for Windows 10 that can show you a list open port in windows, it is like the netstat command line tool but with GUI. It supports IP v4 and V6, it can resolve the remote IP to the domain name and show network statistics.

How To Check If Port Is Open

It is very important to know the ports that are open on your computer because some ports are associated with special services and these ports have to be open for your computer to run properly. It is also important to check if port is open and which ports are open.

To check if port is open, you should enter “netstat -a” in the command line and it will return with a list of open ports.

Open port and hacking:

Apart from the ports that are used for special services, all other ports should be closed because the more open ports you have on your system, the more vulnerable it will be to hacking.

This is because ports are the doors through which access to your computer can be gained.

Firewalls are the only locks that prevent access. Knowing the ports that are open is a step towards safeguarding your computer.

The special ports that should be open and their uses have been outlined below. All other ports should be closed or filter.

Here are the ports:

Port 7:

This port is also referred to as Ping and Echo. It is used to retrieve the IP address of your computer and its gateway. This is done by typing ipconfig in the command prompt. It is also used for troubleshooting. This is done by typing ping and the number of your gateway. You will get a response after.

Port 21:

This is known as the FTP. This is used to either upload or download files to or from a server when websites are being updated.

Port 25:

This port is called SMTP. It works with applications like Thunderbird, Pegasus and the popular Microsoft Outlook to send emails. Gmail, Yahoo mail and Hotmail do not need this port because they are webmail.

Port 53:

This port is also known as DNS. This port helps to convert URL to the IP address of the website. Here is how it works. The computer does not understand the website you type on your web browser and you cannot cram the IP address of websites. So when you type the website, it is converted to the appropriate IP address for your computer through the process known as DNS. The computer now loads the page based on the IP address. Without DNS, you will have to be typing IP address and not the website. Imagine how difficult it will be.

Port 80:

This port is known as HTTP. This is the route through which your computer gains access to the internet or to other websites. If this port is closed, you won’t be able to visit other websites.

Port 110:

This port is called POP3 and it works with the same applications as Port 25 above to receive emails. It does not also work with webmail.

Ports 135 to 139:

This is known as NetBios. This gives you the name of any computer on your network.

Port 443:

This port is known as HTTPS, it does the same thing as Port 80 but for secure websites.

In conclusion:

The above freeware utilities are the answer to the how to check for open ports question and they are useful in being able to troubleshoot network connectivity issues if the need arises and form a part of a network auditing toolkit or basic checks for vulnerabilities where necessary.

4 Easy methods for how to check if port is open on Windows

In this how to check if port is open article, we will try to answer all the how-to questions we receive on our website.

We will add a new question from time to time base on new how to questions that users will ask.

For general question, we will try to answer it for the Windows operation system, assuming it can be asking for Windows, Linux, MAC or Mobile device.

Here is a common question regarding how to check a port is open:

• how to check 443 port open or not?
• how to check if port 443 is open?
• how to check if port 9675 is open?
• how to check port 443 is open?
• how to test port 443 is open?
• how to check if port 25 is open?
• how to check if the port 47827 open?

To check if a port is open or not on your local computer you will have to use a tool.

Using our own Open Port Viewer tool:

You can download our Open Port Viewer tool and run it (right click and run as administrator).

Open Port Viewer is an easy to use GUI tool to get the current list of used ports on your system.

Open port viewer

In the list of ports that you will see, please check if you can see the port you are searching.

Using netstat command line tool:

Another option is to use the netstat command line tool.

To do so, please open cmd as administrator:

1. Press the Windows button
2. Type cmd
3. Right click on Command Prompt.
4. Select Run as administrator.

Open command prompt

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In the command prompt type the following:

netstat -an | find “PORT NUMBER TO FIND”

example to check for 443 with netstat:

netstat -an | find “443”

If you see the port number on the left side (red location on the blow image) the port is open.

how to check if port with netstat

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Read more information about netstat on our netstat command article.

Using telnet command line tool:

Telnet is also a command line tool, to use it you may have to enable it first, on Windows 10.

This is how you enable telnet on windows 10:

1. Open Turn Windows Feature on or off
   1. Press the Windows Button + R
   1. On the Run dialog type: OptionalFeatures
   1. Press enter or Click OK.
2. Fin Telnet client in the list.
3. Mark V near it.
4. Press Ok

Windows Feature

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Open the command prompt as administrator (look above how to open cmd as administrator).

Type the following:

example to check for 443 with telnet:

telnet localhost 443

If you get the following error, the port is close:

Connecting To localhost…Could not open a connection to the host, on port 443: Connect failed

Using putty tool:

To check if the port is open using putty tool, you need to download putty from the internet first.

Putty can open a terminal, like telnet or SSH to connect to a remote host, like the telnet command.

We will use it to connect a local port.

Downloading putty from putty website – Putty

When the site is open scroll down to the Alternative binary files section.

Select the 32-bit or 64-bit version of the tool, and download it to your computer.

Once it finishes downloading open it.

• Set hostname – localhost
• Set Port – The port number
• Select telnet
• Press open

Example of using putty to check port 443:

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If you see the following message the port is close:

putty port close

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In this article, we show you 4 tools that you can use to check if port is open or not.

The above tools are designed to run on Windows operation system and you might need to be an administrator to use them.