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 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 Which Ports Are Open on a Windows 10 PC

Maybe you’re troubleshooting a network connectivity issue for a specific program, and you need to check whether its port access is opened. In this article, we’ll provide you with detailed steps on how to check for open ports on Windows 10.

How to Check Which Ports Are Open on a Windows 10 PC

There are a couple of handy tools you can use for scanning open ports in Windows. We’ll show you how to do so on NetStat, PortQry.exe, and NirSoft CurrPorts.

NetStat

One of the simplest ways to go is NetStat.exe. You can find this tool in the “System32” folder. With NetStat, you can see open ports or ports that a specific host uses.

There are two commands that will be useful, depending on your needs. The first option will list all active ports and the name of the process that uses them. It’s “netstat -ab.” The second option, “netstat -aon” will also provide a process ID you can later check up in the Task Manager.

Here’s what you need to know to fully understand both commands:

Netstat is short for network statistics. It will show protocol statistics as well as the current

TCP and IP network connections. And here’s the explanation of what each letter from the commands mean:

• “a” will display all connections and listening ports.
• “b” will display all executables that are involved in creating each listening port.
• “o” will show the owning process ID that is related to each of the connections.
• “n” will show the addresses and port numbers as numericals.

We’ll start with the simpler form: netstat -ab. Just follow these steps and you’ll be good to go:

1. Run Command Prompt as administrator.
   
2. Run this command: “netstat -ab” and hit enter.
   
3. Wait for the results to load. Port names will be listed next to the local IP address.
   
4. Just look for the port number you need, and if it says “LISTENING” in the “State” column, it means your port is open.
   

The second option will come in handy when the process name isn’t enough to identify what program has a specific port tied up. In that case, just follow these steps:

1. In the search box on your Windows 10, type “cmd.”
   
2. Open the Command Prompt app shown in the results. Make sure to run it as administrator. You can do so by right-clicking on the app and choosing “Run as administrator.”
   
3. Once inside, type the command “netstat -aon” and hit enter.
   
4. You will now see five columns: Protocols, Local Address, Foreign Address, State, and Process ID. In the Local Address, next to the IP address column you will have a port number. For example: 0.0.0.0:135. Here, 135 is the port number.
   
5. In the column called “State”, you will see whether a specific port is opened. For opened ports, it will say “LISTENING.”
   

This is the first part that will get you the port and the process ID. To verify which app uses it, continue with these steps:

1. In Command Prompt, find the PID (the number from the last column) for a specific port.
   
2. Open Task Manager. Use the shortcut Ctrl + Shift + Esc, or right-click on an open space on your Windows taskbar and open the Task Manager.
   
3. Go to the “Details” tab. You’ll see all the processes on your Windows 10. Sort them by the PID column and find the PID that belongs to the port you’re trying to troubleshoot. You can see which app ties the port in the “Description” section.
   

NirSoft CurrPorts

In case you find the Command Prompt solution too difficult – we present you with its simpler alternative. This is a tool that will display your currently opened ports (TCP or IP as well as UDP). You’ll also be able to see information about a specific process such as name, path, version info, and more.

This tool has been around for quite a while and is available for Windows 10. You can find a download link at the bottom of this page.

Note: Make sure you download the right version: they have a 32x bit and 64x bit one. And you won’t need to install this app as it’s portable. You’ll only have to unzip and run it.

Once you have CurrPorts running, we can start with the steps on how to see open ports:

1. You’ll see a list of your computer processes. Sort them by “Local port.”
   
2. Find the port you are troubleshooting.
   
3. You can now see all details such as its process name, PID, full path, etc.
   

Another way is to simply double-click on a process to see all of its details in a single window.

PortQry.exe

Here’s another handy tool that will let you scan open ports. You just have to download and extract the tool and run it through Command Prompt. You’ll open Command Prompt by searching for “cmd” in the search box on your Windows, right-clicking on it, and choosing “Run as administrator.”

With portqry.exe, you will be inserting specific parameters you find in the executable’s folder. For example, if you run “portqry.exe -local”, this will show used TCP and UDP ports for a local host. In addition to all parameters you can see in NetStat, Portqry.exe also shows you a number of port mappings as well as the number of ports in each state.

You can also check for open ports for a remote host. Just run this command in the Command Prompt: “portqry.exe -n [hostname/IP]” Make sure to replace the hostname and IP by the remote host’s name and IP address.

If you want to look for a specific port, you can run this command: “-e [port_number]”.

Additional FAQs

How Do I Check if Port 3306 Is Open in Windows 10?

If you read the main part of this article, you will have an idea of how to check if a specific port is “listening” – in this case, port 3306. Just to make things simpler, here’s a brief overview:

You have three options: the first one is via NetStat, and the second one is via CurrPorts.

We recommend NetStat, as you won’t have to download new software for this:

• Run Command Prompt as administrator.

• Run this command: “netstat -ab” and hit enter.

• Wait for the results to load. Port names will be listed next to the local IP address.

• Just look for the port number you need, in this case 3306. You can press Ctrl + F and type “3306” in the word box. If the port is open, it will show in the results.

To check if port 3306 is open via CurrPorts, just follow the steps above from the “NirSoft CurrPorts” section. In step 2, look for port “3306” from the list. If the port is open, it will show in the list.

For PortQry.exe, run this command in Command Prompt “-e [3306]” and hit enter.

Configuring Open Ports in Windows 10

Knowing how to check whether a specific port is open or not can come in handy if you’re troubleshooting a program network connection. Luckily, there’s an easy way to do that.

We recommend using NetStat via Command Prompt as it’s in-built and will usually give you all the details you need. There might be a few extra steps required compared to CurrPorts, but you don’t have to download anything.

Which way do you find to be the most convenient for checking open ports on Windows 10? Let us know in the comments section below.