# How to find the process that is using a port

> Learn how to find which process is listening on a port using the lsof -i command, then stop it with kill so you can free up a busy port like 3000.

Author: [Flavio Copes](https://flaviocopes.com/about/) | Published: 2020-08-14 | Topics: [CLI](https://flaviocopes.com/tags/cli/) | Canonical: https://flaviocopes.com/command-using-port/

Sometimes when developing multiple applications at once, or trying out demos, I end up with multiple programs running on different ports on my computer: `3000`, `3001`, `1313`, and so on.

If I don't pay close attention, I might forget which application is running on a specific port.

How can we determine which program is listening on a port?

The `lsof` command helps us do that!

Running

```
lsof -i :1313
```

Will tell me the command that's currently listening on port 1313:

```
COMMAND  PID   USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
hugo    8698 fla 4764u  IPv4 0xc72ca30d18e45ef9      0t0  TCP localhost:bmc_patroldb (LISTEN)
```

In this case it's the `hugo` command, with PID 8698.

If I want to terminate that program, I can just run `kill 8698`.