How to Check for Ports in Use in Windows 10

At any one time, there’s a whole bunch of information being sent between your Windows 10 PC and the endless void of the Internet. This is done using a process whereby network-dependent processes seek out TCP and UDP ports, which they use to communicate with the Internet. First, your data gets sent to remote ports at the destination or website your processes are trying to connect to, then it gets received at local ports back on your PC.

Most of the time, Windows 10 knows how to manage ports and ensure that traffic is being directed through the right ports so that those processes can connect with what they need to. But sometimes two processes may be assigned to one port, or maybe you just want to get a better picture of your network traffic and what’s going in and out.

That’s why wrote this guide that shows you how to get an overview of your ports and see which applications are using which ports.

Use Nirsoft CurrPorts

NirSoft is one of the best indie software developers, giving us great utilities, like PassView and WirelessKeyView. While some people will prefer checking their ports without installing third-party software (in which case, scroll down to the CMD method), CurrPorts is easily the fastest and most convenient way to view your ports.

Once you’ve installed CurrPorts, just open it to see a list of all your ports currently in use. If you’re looking for local ports in use, just click the “Local Port” column at the top to order the list by port number (handy if you’re looking for a specific one). You can do the same thing with remote ports, too.

If you want to really find specific ports, click the “Advanced Filters” icon at the top and enter your string in the format they suggest. It should look something like the below image.

Hit OK when you’re ready, and the list will filter down to your queries.

Command Prompt Method

The integrated – though not necessarily the simplest – way to check open ports is to use the trusty command prompt.

Click the Start button, type cmd , then right-click “Command Prompt” when it shows up in the search results. Click “Run as administrator.”

Once you’re in the elevated command prompt, enter the following command:

This will steadily bring up a list of ports that is probably quite long, along with the Windows processes that are using them. (You can press Ctrl + A , then Ctrl + C to copy all information to the clipboard.) On the average PC, there will be two main local IP addresses that contain ports on your PC.

The first, in our case, is “127.0.0.1.” This IP address is otherwise known as “localhost” or a “loopback address,” and any process listening to ports here is communicating internally on your local network without using any network interface. The actual port is the number you see after the colon. (See image below.)

The bulk of your processes will probably be listening to ports prefixed with “192.168.xxx.xxx,” which is your IP address. This means the processes you see listed here are listening for communications from remote Internet locations (such as websites). Again, the port number is the number after the colon.

TCPView

If you don’t mind installing a third-party app and want to have more control over what’s going on with all your ports, you can use a lightweight app called TCPView. This immediately brings up a list of processes and their associated ports.

What make this better than the command prompt is that you can actively see the ports opening, closing and sending packets. Just look for the green, red and yellow highlights. You can also reorder the list by clicking the column headings, making it easier to find the process you want or two separate processes vying for the same port.

If you do find a process or connection you want to close, just right-click that process. You can then select “End process,” which is exactly the same function as the one in Windows task manager. Or you can click “Close Connection” to leave the process open but stop it from listening on a given port.

If you’re having some trouble in Windows 10, then see whether a Windows update may be causing it. We also have a handy guide for managing the health of your hard drive in Windows 10.

Related:

Content Manager at Make Tech Easier. Enjoys Android, Windows, and tinkering with retro console emulation to breaking point.

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.

How to Check Open Ports in Windows 10 Using CMD

In this article, you will see the procedure to Check Open Ports in Windows 10 Using CMD (or Command Prompt). When an app uses a TCP/IP port on your device in order to access a network, that port would be locked out – no other program may be able to use it. And while everything related to ports and traffic is usually taken care of on its own by the system, there might be situations when you might have to know the application that is blocking a specific port.

Here you can find some built-in ways to do so- specifically the ways to check open ports using CMD or Command Prompt. Apart from using the Command Prompt, you can even consider using some third-party applications that can easily list the ports and the apps or processes that are using them.

Way to Check Open Ports in Windows 10 Using CMD

Here is how to check open Ports in Windows 10 Using CMD –

To find port-use with process names

Follow along with these steps to get the list of ports in use and the names of the processes tied up with them respectively.

Step-1: Open Run dialog box by pressing Win+R hotkeys. Type cmd in the text box and hit Shift + Ctrl + Enter keys altogether.

Step-2: Hit Yes on the UAC prompt.

Step-3: This will let you access an elevated Command Prompt on the screen. Here, type in or copy-paste the below-given code and hit Enter.

Wait for the entire result to load. Once you successfully run this command, simply scroll down to the port number you want to check. As shown below, you’ll be able to see the process’ name respectively below the port it is linked to.

To find port-use with the process identifiers

Usually, identifying the application which represented by a specific process name can be tricky. This method might help you identify the application that a process relates to.

Here also, first of all, launch the “Command Prompt” with admin rights using any of your preferred methods.

Copy-paste or type the below code and ensure to hit Enter.

Finally, the result now will contain the “PID” or the process identifiers instead of the names. Simply scroll down to the port you want to check and note the PID corresponding to it.

Moving ahead, open Task Manager. To do so, perform a right-click on the taskbar and select the option namely “Task Manager”.

Go to the Processes tab. Right-click on the Name column and choose PID (see snapshot).

You just need to find the PID you note earlier. The ‘Name’ column corresponding to the PID must reveal the application associated with the port.