Something is already running on port 3000

Question

I have tried to run my project on my localhost but it is saying Something is already running on your port 3000.

Answer 1

After all the googled advices failed to solve the problem of why already working project started failing:

First running: npm install

then running: npm start worked for me.

Answer 2

You can run this Command npx kill-port 3000 . This command keeps empty your 3000 port

Answer 3

Launch Task Manager, find all the programs/tasks that are related Nodejs and stop them.

Answer 4

I know this is late , but if anyone faces the same issue might want to try this

sudo kill -9 $(sudo lsof -t -i:9001)

where, 9001 is your port number.

Answer 5

 

On React - you can run an already created React single-page application (SPA) by

npm start command.

That may start your locally hosting development server and runs your app at:

http://localhost:3000/ which is equivalent to: 127.0.0.1:3000 address

127.0.0.1 is the default localhost IP number while the default port number set by

create-react-app package is 3000.

When getting: “Something is already running on port 3000" failure error message you may think that the port captured by another process running on your machine but you’ll find that it is captured permanently as if it runs on 0.0.0.0:3000 address

Solution:

In your project libraries created by create-react-app script navigate to:

node_modules/react-scripts/scripts/start.js

While running npm start command - the start.js script is being called and executed

There at start.js file in you editor find the above line:

const HOST = process.env.HOST || '0.0.0.0';

 and change it to:

const HOST = process.env.HOST || '127.0.0.1';

 

save and run your web app again at: http://localhost:3000/ or http://127.0.0.1:3000

 

 

 

Answer 6

If you're using Linux, you can run the following commands on your console:

fuser -n tcp 3000

The command above will return the task ID of the program that is currently using the port. Then you will have to run

kill -9 [#task]

with the task ID. (Just replace all the '[#task]' by the task ID returned)