Django Server Error: Port Is Already in Use

netstat -ntlp

It will show something like this.

   Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State           PID/Program name    
tcp        0      0 127.0.0.1:8000          0.0.0.0:*               LISTEN      6599/python         
tcp        0      0 127.0.0.1:27017         0.0.0.0:*               LISTEN      -                   
tcp        0      0 192.168.124.1:53        0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      -                   
tcp6       0      0 :::3306                 :::*                    LISTEN     

So now just close the port in which Django/python running already by killing the process associated with it.

kill -9 PID

in my case

kill -9 6599

Now run your Django app.

ps aux | grep -i manage

after that you will see all process 


ubuntu@ip-10-154-22-113:~/django-apps/projectname$ ps aux | grep -i manage
ubuntu    3439  0.0  2.3  40228 14064 pts/0    T    06:47   0:00 python manage.py runserver project name
ubuntu    3440  1.4  9.7 200996 59324 pts/0    Tl   06:47   2:52 /usr/bin/python manage.py runserver project name
ubuntu    4581  0.0  0.1   7988   892 pts/0    S+   10:02   0:00 grep --color=auto -i manage


kill -9 process id


e.d kill -9 3440


`enter code here`after that :

python manage.py runserver project name

By default, the runserver command starts the development server on the internal IP at port 8000.

If you want to change the server’s port, pass it as a command-line argument. For instance, this command starts the server on port 8080:

python manage.py runserver 8080

lsof -t -i tcp:8000 | xargs kill -9

Sorry for comment in an old post but It may help people

Just type this on your terminal

killall -9 python3

It will kill all python3 running on your machine and it will free your all port. Greatly help me when to work in Django project.

We don't use this command { sudo lsof -t -i tcp:8000 | xargs kill -9 } Because it's close all tabs...You should use to

ps -ef | grep python

kill -9 process_id

ps -ef | grep python (show all process with id)

kill -9 11633 (11633 is a process id to :- /bin/python manage.py runserver)

>> ps aux | grep manage

 ubuntu    3438  127.0.0  2.3  40256 14064 pts/0    T    06:47   0:00 python manage.py runserver

>> kill -9 3438

Type 'fg' as command after that Ctrl-C.
Command:
Fg will show which is running on background. After that Ctrl-C will stop it.

fg
ctl-c

This is an expansion on Mounir's answer. I've added a bash script that covers this for you. Just run ./scripts/runserver.sh instead of ./manage.py runserver and it'll work exactly the same way.

#!/bin/bash

pid=$(ps aux | grep "./manage.py runserver" | grep -v grep | head -1 | xargs | cut -f2 -d" ")

if [[ -n "$pid" ]]; then
    kill $pid
fi

fuser -k 8000/tcp
./manage.py runserver

1. In terminal, Type ps aux | grep runserver
2. Hit Enter
3. Use PID among the result execute kill -9 <PID>

For an instance, If result of step 1 is as follow

root      1041  0.0  0.1 266912 34580 pts/3    S+   11:31   0:01 python3 manage.py runserver 0.0.0.0:3030
root      1696  4.5  0.1 126128 40708 ?        S    Feb14 925:43 /usr/local/bin/python manage.py runserver 0.0.0.0:8000

1041 and 1696 are PIDs. We need to choose whichever process we want to kill among them.

For me, this happens because my API request in Postman is being intercepted by a debugger breakpoint in my app... leaving the request hanging. If I cancel the request in Postman before killing my app's server, the error does not happen in the first place.

--> So try cancelling any open requests you are making in other programs.

On macOS, I have been using sudo lsof -t -i tcp:8000 | xargs kill -9 when I forget to cancel the open http request in order to solve error = That port is already in use. This also, complete closes my Postman app, which is why my first solution is better.

Click the arrow in the screenshot and find the bash with already running Django server. You were getting the message because your server was already running and you tried to start the server again.

if you have face this problem in mac you just need to open activity monitor and force quite python then try again

In case You are using the VSC's screen terminal, The error might be due to the fact that you already runserver in some other shell.

Just click on the dropbox on the left of the + sign in the header of the terminal of VSC and select some other shell and check if the server is already running there. Quit that server and you are ready to launch a another server.

Dont use CTRL + Z to stop server, use CTRL + C to stop the server, I had also had the same problem in my linux (fedora) , I used to stop the server using CTRL + Z and again I used to kill the server using sudo fuser -k 8000/tcp command, which worked fine. But later when I started using CTRL + C , I didnot get that port running issue anymore.