“Port 4200 is already in use” when running the ng serve command

Question

I am learning angular 2 and for the first time I am using the angular CLI project to create a sandbox project.

I was able to run the command \"ng serve\" and it wor

Answer 1

VScode terminal in Ubuntu OS use following command to kill process

lsof -t -i tcp:4200 | xargs kill -9

Answer 2

I am sharing this as the fowling two commands did not do the job on my mac:

sudo kill $(sudo lsof -t -i:4200)

sudo kill `sudo lsof -t -i:4200`

The following one did, but if you were using the integrated terminal in Visual Code, try to use your machine terminal and add the fowling command:

lsof -t -i tcp:4200 | xargs kill -9

Answer 3

Right now you can set --port 0 to get a free port.

ng serve --port 0 // will get a free port for you

Answer 4

This is what I used to kill the progress on port 4200

For linux users:

sudo kill $(sudo lsof -t -i:4200)

You could also try this:

sudo kill `sudo lsof -t -i:4200`

For windows users:

Port number 4200 is already in use. Open the cmd as administrator. Type below command in cmd:

netstat -a -n -o

And then, find port with port number 4200 by right click on terminal and click find, enter 4200 in "find what" and click "find next": Let say you found that port number 4200 is used by pid 18932. Type below command in cmd:

taskkill -f /pid 18932

For UNIX:

alias ngf='kill -9  $(lsof -t -i:4200);ng serve'

Now run ngf (instead of ng serve) in terminal from the project folder. This will kill all processes using the port 4200 and runs your Angular project.

Answer 5

In summary there are more than one solution : 1 ) By using another port to define port number ,

ng serve --open --port 4201

2) by killing the process

ctrl + c // for kill
Close all node terminal which is related for running the app.

3) Type

netstat -a -n -o

in command prompt then find the related port PID and kill it by

taskkill /F /PID (pid number)

4) Type netstat -ano|findstr :4200

took the foreign address PID which contain the port number and then kill it by

taskkill /PID (pid number)/F

Answer 6

For Ubndu 18.04 sudo lsof -t -i tcp:3000 | xargs kill -9

Its happen when port was unsucessfully terminated so this command will terminat it 4200 or 3000 or3300 any