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

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.


Open your cmd.exe as administrator,

then Find the PID of port 4200

netstat -ano | findstr :4200

Pid for port 4200

Here i have 3 PID :

  • Red one is from "ng-serve" (127.0.0.1:4200) that LISTENING
  • Green one is from "your browser"

kill only port 4200 (kill the red PID): 

taskkill /PID 15940 /F

note : kill the green one will only lead your browser closed by force.

taskkill pid 15940

now you can do "ng-serve" to start your angular app at the same port 4200

Additional Stuff :

One liner : After looking a way to optimize this, Here is the One-liner command of this answer : (special thanks to : Josep Alsina for this tips)

for /f "tokens=5" %a in ('netstat -ano ^| find "4200" ^| find "LISTENING"') do taskkill /f /pid %a

Tags:

Angular

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