How to Find Which Process Is Listening on a Port in Windows

When you're debugging a network issue or troubleshooting a blocked service, it helps to know which process is listening on a given TCP or UDP port. In this guide, you'll use built-in Windows tools to find that out.

Prerequisites

You'll need:

• A Windows machine (10, 11, or Server)
• Administrator access to run some commands

Step 1: Check Listening Ports with netstat

The netstat command shows open connections and listening ports.

Run this from an elevated Command Prompt:

netstat -aon | findstr LISTENING

This lists all listening TCP ports along with their associated process IDs (PIDs).

Example output:

  TCP    0.0.0.0:80       0.0.0.0:0       LISTENING       1248
  TCP    [::]:443         [::]:0          LISTENING       1580

Look at the PID in the last column. This is the identifier for the process using that port.

Step 2: Match the PID to a Process

Once you have the PID, use tasklist to find the associated application:

tasklist /FI "PID eq 1248"

This might return:

Image Name                     PID Session Name        Mem Usage
========================= ======== ================ ============
nginx.exe                     1248 Console             10,300 K

Now you know that nginx.exe is using port 80.

Step 3: Use PowerShell to Combine the Two

If you prefer PowerShell, you can fetch both the port and process name together:

Get-NetTCPConnection -State Listen | ForEach-Object {
  $proc = Get-Process -Id $_.OwningProcess -ErrorAction SilentlyContinue
  [PSCustomObject]@{
    LocalPort = $_.LocalPort
    PID       = $_.OwningProcess
    Process   = $proc.Name
  }
}

This outputs a list of listening ports along with their owning processes:

LocalPort PID  Process
--------- ---  -------
80        1248 nginx
443       1580 nginx

To filter by a specific port:

Get-NetTCPConnection -LocalPort 3306

Step 4, Use Resource Monitor (Optional GUI)

If you prefer using a graphical interface:

1. Press Ctrl + Shift + Esc to open Task Manager
2. Go to the Performance tab
3. Click Open Resource Monitor at the bottom
4. Switch to the Network tab and expand Listening Ports

This view shows which ports are open and which processes are using them.

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That's it, now you can quickly find out what's occupying a port in Windows using either the terminal or the GUI. This comes in handy when diagnosing port conflicts or service issues.