Reputation: 4031

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

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 works great. I wanted to stop it from running so I ran "Control Z".

When I tried to run the "ng-serve" command again it gives me "Port 4200 is already in use."

I ran "PS" to get a list of the PID and killed the PID for the angular-cli and ran "ng-serve" again still it gives the same port in use error.

Upvotes: 309

Answers (30)

M. Al Jumaily

Reputation: 973

A one-line on macOS would be to kill the port, thanks to Claudio Holanda, and then reinitiate it again:

npx kill-port 4200 && ng serve -o

It still requires CMD + Z to suspend ng serve.

Upvotes: 1

Sara Medhat

Reputation: 31

just press q and it will close

Upvotes: 0

Emir Mamashov

Reputation: 1168

Do not use ctrl+Z, to stop the process you must use ctrl+C

Upvotes: 38

abduljalil

Reputation: 153

For me, this cmd worked Ubuntu

sudo fuser -k 4200/tcp for killing other ports

Upvotes: 2

Kapilfreeman

Reputation: 1185

If you have npm installed, which I assume you have if you are using angular, then you can simply run npx kill-port 4200. That's it.

Upvotes: 68

Baran Goodarzi

Reputation: 91

With these three commands:

netstat -anb | findstr 4200
netstat -anbo | findstr 4200
taskkill -f /pid 22416

Cmd => should be run as an administrator

First: check if it is listening or not

C:\Windows\system32>netstat -anb | findstr 4200

Output:

TCP  127.0.0.1:4200     0.0.0.0:0      LISTENING

Second: Find IP

C:\Windows\system32>netstat -anbo | findstr 4200

Output:

TCP    127.0.0.1:4200     0.0.0.0:0    LISTENING    22416

Third: kill the port

C:\Windows\system32>taskkill -f /pid 22416

SUCCESS: The process with PID 22416 has been terminated.

You should find your own pid;

Upvotes: 5

vikashjha.tp

Reputation: 45

ng serve --open

assigns a local host to host the project.On running the same command in same directory the system assigns localhost:port where port is already in use. To override this issue one can easily run the following command:

ng serve --port

this will assign a new port for the project without disturbing the present local host port.

Upvotes: 0

Kavinda Senarathne

Reputation: 2004

Port 4200 is already in use.Use -port to specify a different port error Reasons An existing application(not angular) in your system using the port number 4200. This is a very rare scenario. In this case, you need to change the port number of angular application as mentioned below. You already ran ng serve and to exit the application you typed Control Z (Ctrl+Z), And then you typed ng serve then you will get port 4200 is already in use_ error. In this case, you need to kill the previous process.

To change the port number for our angular application use the below command

ng serve --port 4201

Now type ng serve

Our angular application will be running on http://localhost:4201

To fix port 4200 is already in use error in In Mac & Linux OS (Ubuntu etc) use the following commands

sudo kill $(sudo lsof -t -i:4200) Or
sudo kill `sudo lsof -t -i:4200` Or
sudo lsof -t -i tcp:4200 | xargs kill -9

In Window operating system open command prompt. Use the following command to fix port 4200 is already in use error.

netstat -a -n -o | findStr "4200"`

Take the process id and kill the process using the following command

taskkill -f /pid 11128

Upvotes: 8

JoBaHP

Reputation: 103

On my Ubuntu i had typo crl+z to close terminal and after that i couldn't acces localhost:4200. The only solutin was to do:

$ sudo fuser -k 4200/tcp

and after that restart the server.

Upvotes: 1

Soft Dev Ahmad yar khan

Reputation: 494

For windows users:

step 1.Port number 4200 is already in use. Open the cmd as administrator. Type below command in cmd:

netstat -a -n -o

enter image description here

Find the PID of the process that you want to kill.

step 2.command in cmd:

taskkill /F /PID 6500

step 3: Now, Type :

ng serve to start your angular app at the same port 4200

Upvotes: 0

Surendranath Sonawane

Reputation: 1737

VScode terminal in Ubuntu OS use following command to kill process

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

Upvotes: 7

HeshanHH

Reputation: 703

close the command prompt (cmd) then use text editor terminal or use only cmd to run commands.

in my case this is the problem and how i solved it.

most of the time you are created angular app using command prompt. then you trying to run the app terminal in inside of the text editor. whenever you trying to save you can see some stuff running on the windows command prompt. so just close it and run the command in the terminal of the text editor.

Upvotes: 0

user12465043

Reputation:

It seems like another program is using your default port 4200. Good thing is, ports above 4200 are usually free. Just pick another one. For example:

ng serve --port 4210

Upvotes: 1

Bart Hoekstra

Reputation: 6164

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.

Upvotes: 523

Kranthi Golamari

Reputation: 1

To fix this issue in Windows OS, open Task Manager, and terminate the process.

TaskManager

Upvotes: 0

Alejandro Giraldo

Reputation: 629

I had big troubles with this, and I was even trying with many others ports and nothing.

I did npm install [email protected] and it solved the problem. For some reason the typescript version was causing a conflict and using yarn or ng serve were not working.

hope this works for anyone else with the same issue.

Upvotes: 0

Yevhen Laichenkov

Reputation: 8692

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

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

Upvotes: 8

DIBYA RANJAN TRIPATHY

Reputation: 272

If you are using VSCode, you have the option to kill terminal and add a new terminal. Close the tab and open a new tab. It worked for me.

Edited: Use ctrl+c and press y. With out killing terminal also, You can proceed. If you want to open a new instance of visual studio and run a different application , you can use ng serve --port 4401.

Upvotes: 2

Alien

Reputation: 15908

In my case none of the above mentioned worked.

UBUNTU 18.04 VERSION

Below command worked.

sudo kill -9 $(lsof -i tcp:4200 -t)

Upvotes: 3

Priyanka Arora

Reputation: 457

I too faced similar problem and problem was basically that I had opened multiple running terminals in powershell. So make sure you Ctrl+c all others.

Upvotes: 0

saravana va

Reputation: 1149

To stop all the local port running in windows, use this simple comment alone instead searching for pid separatly using netstat,

It find all the pid and stop the local port which is currently running,

taskkill /im node.exe /f

Upvotes: 5

user2642281

Reputation: 145

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

Upvotes: 1

Ahmed Hadi

Reputation: 121

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

Upvotes: 8

Spirit

Reputation: 660

With ctrl + z you put the program in the background. On Linux you can get the session back in the foreground with the following command:

fg ng serve

You don't need to kill the process.

Upvotes: 5

Mohaimin Moin

Reputation: 841

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

Upvotes: 10

Dibish

Reputation: 9303

To Access project outside localhost

Example:

ng serve --host 192.168.2.2:7006

Upvotes: -1

Alekya

Reputation: 243

Instead of killing the whole process or using ctrl+z, you can simply use ctrl+c to stop the server and can happily use ng serve command without any errors or if you want to run on a different port simply use this command ng serve --port portno(ex: ng serve --port 4201).

Upvotes: 1