{"id":681,"date":"2026-11-10T10:58:12","date_gmt":"2026-11-10T10:58:12","guid":{"rendered":"https:\/\/getserverexplorer.app\/?p=681"},"modified":"2026-11-08T11:37:54","modified_gmt":"2026-11-08T11:37:54","slug":"kill-process-on-port-linux","status":"publish","type":"post","link":"https:\/\/getserverexplorer.app\/index.php\/2026\/11\/10\/kill-process-on-port-linux\/","title":{"rendered":"How to Find and Kill a Process on a Port in Linux"},"content":{"rendered":"\n

<\/p>\n\n\n\n

You start your Node.js app, and the terminal throws an error:<\/p>\n\n\n\n

Error: listen EADDRINUSE: address already in use :::3000<\/code><\/pre>\n\n\n\n
Something is already listening on port 3000<\/strong>. It might be an older instance of your app, a service managed by systemd, or a Docker container.<\/p>\n\n\n\n
Here’s how to find the process, stop it safely, and avoid the same problem next time.<\/p>\n\n\n\n
1. Find Which Process Is Using the Port<\/h2>\n\n\n\n
On most modern Linux servers, ss<\/code> is a good place to start:<\/p>\n\n\n\n
sudo ss -ltnp '( sport = :3000 )'<\/code><\/pre>\n\n\n\n
The output shows listening TCP sockets, including the local address and, when available, the process name and PID. The sudo<\/code> prefix helps reveal processes owned by other users.<\/p>\n\n\n\n
You can also use lsof<\/code> if it is installed:<\/p>\n\n\n\n
sudo lsof -nP -iTCP:3000 -sTCP:LISTEN<\/code><\/pre>\n\n\n\n
Example output:<\/p>\n\n\n\n
COMMAND   PID USER   FD   TYPE DEVICE SIZE\/OFF NODE NAME\nnode     2481 app    21u  IPv6  12345      0t0  TCP *:3000 (LISTEN)<\/code><\/pre>\n\n\n\n
Here, 2481<\/strong> is the process ID (PID). Don’t kill it yet: first check what it is.<\/p>\n\n\n\n
ps -fp 2481<\/code><\/pre>\n\n\n\n
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Note:<\/strong> If ss<\/code> returns no listener, check that you are looking at the correct server and network namespace. A Docker-published port may be managed differently from a regular host process.<\/p>\n<\/blockquote>\n\n\n\n
2. Find the Port Visually in Server Explorer<\/h2>\n\n\n\n
If you prefer a graphical view, connect to your VPS in Server Explorer<\/strong> and open Monitoring \u2192 Ports<\/strong>.<\/p>\n\n\n\n
The Ports tab shows listening addresses, protocols, associated commands, and PIDs where available. Use the search field to look for 3000<\/code>, an address, or a process name.<\/p>\n\n\n\n
\"Server<\/figure>\n\n\n\n
\"Server
Server Explorer’s Ports view helps identify which process is associated with a listening port.<\/em><\/figcaption><\/figure>\n\n\n
\n \n \n  \n  \n  \n <\/g>\n \n  \n <\/g>\n \n  \n  \n <\/g>\n <\/g>\n<\/svg>\n 
\n  <\/span>Server Explorer<\/span>\n  
Bring your servers into focus.<\/h3>\n  
A desktop app for macOS and Windows. Connect over SSH.<\/p> <\/div>\n Download\u2197<\/span><\/a>\n<\/div>\n\n\n\n\n
In the screenshot, the Ports view lists TCP and UDP entries and their PIDs. Its context menu includes actions to copy an address or port. It does not show a kill action in this view.<\/strong> Once you identify the PID, switch to Processes<\/strong>.<\/p>\n\n\n\n
<\/p>\n\n\n\n
3. Stop the Process Safely<\/h2>\n\n\n\n
If you have confirmed that the process should be stopped, first try a normal termination signal:<\/p>\n\n\n\n
kill 2481<\/code><\/pre>\n\n\n\n
This sends SIGTERM<\/code>, giving the process a chance to shut down gracefully. Verify that the port is free:<\/p>\n\n\n\n
sudo ss -ltnp '( sport = :3000 )'<\/code><\/pre>\n\n\n\n
If the process ignores termination, investigate why before escalating. As a last resort:<\/p>\n\n\n\n
kill -9 2481<\/code><\/pre>\n\n\n\n
SIGKILL<\/code> stops a process immediately and prevents graceful cleanup. Avoid it when a normal shutdown is possible.<\/p>\n\n\n\n
Stop a process with Server Explorer<\/h3>\n\n\n\n
In Monitoring \u2192 Processes<\/strong>, search for the PID or command you identified in the Ports tab. Review the matching entry, then use the stop control if you’re sure it is the correct process.<\/p>\n\n\n\n
\"Server<\/figure>\n\n\n\n
\"Server
Find a process by PID or command in Server Explorer’s Processes view before stopping it.<\/em><\/figcaption><\/figure>\n\n\n
\n \n \n  \n  \n  \n <\/g>\n \n  \n <\/g>\n \n  \n  \n <\/g>\n <\/g>\n<\/svg>\n 
\n  <\/span>Server Explorer<\/span>\n  
Bring your servers into focus.<\/h3>\n  
A desktop app for macOS and Windows. Connect over SSH.<\/p> <\/div>\n Download\u2197<\/span><\/a>\n<\/div>\n\n\n\n\n
This is particularly useful when you manage several VPS instances and want to confirm which server and process you’re acting on.<\/p>\n\n\n\n
Important:<\/strong> Do not terminate system processes such as PID 1, sshd<\/code>, or other critical services just because they appear in the list. Stopping the wrong process can interrupt your server or disconnect your SSH session.<\/p>\n\n\n\n
4. What If the Process Keeps Coming Back?<\/h2>\n\n\n\n
A process that immediately restarts is often being supervised. Killing its PID may only provide a temporary fix.<\/p>\n\n\n\n
systemd:<\/strong> Check the service and stop it through its manager:<\/p>\n\n\n\n
sudo systemctl status my-app.service\nsudo systemctl stop my-app.service<\/code><\/pre>\n\n\n\n
PM2:<\/strong> If your Node.js app is managed by PM2, inspect its process list and stop the intended app:<\/p>\n\n\n\n
pm2 list\npm2 stop my-app<\/code><\/pre>\n\n\n\n
Run PM2 commands as the user that owns the PM2 process list.<\/p>\n\n\n\n
Docker:<\/strong> Check running containers and stop the relevant container instead of blindly killing host PIDs:<\/p>\n\n\n\n
docker ps\ndocker stop my-container<\/code><\/pre>\n\n\n\n
If the container restarts, inspect its restart policy and logs. If port 3000 is published by Docker, check the container’s port mappings before changing anything.<\/p>\n\n\n\n
5. Prevent Port Conflicts Next Time<\/h2>\n\n\n\n
A few habits help prevent repeated EADDRINUSE<\/code> errors:<\/p>\n\n\n\n