How to find the process that is using a 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.
→ I wrote 17 books to help you become a better developer:
- C Handbook
- Command Line Handbook
- CSS Handbook
- Express Handbook
- Git Cheat Sheet
- Go Handbook
- HTML Handbook
- JS Handbook
- Laravel Handbook
- Next.js Handbook
- Node.js Handbook
- PHP Handbook
- Python Handbook
- React Handbook
- SQL Handbook
- Svelte Handbook
- Swift Handbook
Also, JOIN MY CODING BOOTCAMP, an amazing cohort course that will be a huge step up in your coding career - covering React, Next.js - next edition February 2025