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 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

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Only thing that works for me is to restart my system   device     Using Webstorm IDE by JetBrains

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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

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We can forcefully kill the port by following command   kill -2   lsof -t -i 4200

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Not ctrl Z   you must run for stop ctrl C

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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

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If you compiling your angular JS code in both CMD and IDE then this issue occur  In CMD  your angular JS code compile automatically whenever you change your angular JS code in IDE and then your IDE want to occupy the same port i e 4200 which is occupied by CMD already So  there is a simple solution for this issue  just close your cmd while compiling your code in IDE

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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

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For Windows   Open Command Prompt and  type  netstat -a -o -n  Find the PID of the process that you want to kill   Type  taskkill  F  PID 16876  This one 16876 - is the PID for the process that I want to kill - in that case  the process is 4200 - check the attached file you can give any port number     Now  Type   ng serve to start your angular app at the same port 4200

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When you use Ctrl Z  you are going to suspend a running task but not to kill it  You can later use command fg to resume the task   If you want to quit ng serve  you should use Ctrl C instead  in which will also release the 4200 port

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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

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In my case none of the above mentioned worked   UBUNTU 18 04 VERSION  Below command worked   sudo kill -9   lsof -i tcp 4200 -t

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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

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Use this command to kill ng    pkill -9 ng

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netstat -anp   grep   4200    This will tell you who s got the port

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VScode terminal in Ubuntu OS use following command to kill process  lsof -t -i tcp 4200   xargs kill -9

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It says already we are running the services with port no 4200 please use another port instead of 4200  Below command is to solve the problem     ng serve --port 4300

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netstat -plnet  tcp        0      0 127 0 0 1 4200          0 0 0 0                 LISTEN      1001       63955       7077 ng   kill -9 7077  again start your ng serve

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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

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Open your cmd exe as administrator   then Find the PID of port 4200  netstat -ano   findstr  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     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

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ng serve --port 122345 is worked fine for me

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

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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

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I also faced the same error msg  so i tried ng serve --port 12012 and it worked fine

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I was facing the same issue every time I have to kill the port   I tried   node modules  bin ng serve --proxy-config proxy conf json --host 0 0 0 0 Instead of npm start and its works

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On linux mint 17   this is working    kill -9   lsof -t -i 4200

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The most simple one line command    sudo fuser -k 4200 tcp

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Right now you can set --port 0 to get a free port   ng serve --port 0    will get a free port for you

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You can also try with this to run your application in visual studio code -      ng serve --open --port 4201   you can give any port number

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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

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It is possible to change port in  angular-cli file  For example    defaults          styleExt    css        component            serve            port   4205             In addition  it is necessary to add this to your package json    ng    ng    start    ng serve

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Port 4200 is already in use  Use  --port  to specify a different port   This means that you already have another service running on port 4200  If this is the case you can either   shut down the other service  use the --port flag when running ng serve like this    ng serve --port 9001   Another thing to notice is that  on some machines  the domain localhost may not work  You may see a set of numbers such as 127 0 0 1  When you run ng serve it should show you what URL the server is running on  so be sure to read the messages on your machine to find your exact development URL

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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

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you can use fuser -k 4200 tcp if it is Linux Operating system

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On Mac OS X you need the following command   sudo lsof -t -i tcp 4200   xargs kill -9  Remember you need to kill Angular s web server with Command C

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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

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I had big troubles with this  and I was even trying with many others ports and nothing    I did npm install typescript 2 8 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

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Kill process and close the terminal which you used for running the app on that port

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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

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ng serve --port 4201 --live-reload-port 4200   and access using localhost 4201  This should work as a temporary solution   or   try listing port usage using lsof -i 4200 and kill it manually using sudo kill -9  lt Process PID using port 4200 gt

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ng serve --port  lt YOUR GIVEN PORT NUMBER gt   You should try above command to run on your given port

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In Windows  In command prompt which is running your ng serve just click and press keys   ctrl   c   It will ask you  Terminate batch job  Y N    and you type Y

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Just restart the IDE you are using  then it will work

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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  amp  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  quot 4200 quot    Take the process id and kill the process using the following command taskkill -f  pid 11128

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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

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To Access project outside localhost  Example    ng serve --host 192 168 2 2 7006

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As first step after any changes  I use ng build  then ng serve  It works without any problems

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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

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

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