Hi Everyone
I have downloaded a few react project from github for study purpose. When I run the project with the command npm start I got this error message : "Something is already running on port 3000".
Now I if I restart the PC then I can run the project again. How can I run the projects without restarting the PC ? What's the solution ?
Top comments (22)
You can simply execute
npx kill-port 3000to kill the process which is using port 3000this isn't working I also tried, but still seeing ? Something is already running on port 3000. in my terminal, I restarted as well still same issue
Even after restarting the machine you're getting the error means something is added as a service which automatically starts on restarting the machine. You need to identify that and remove it.
How do I check which service is running , because I have tested and nothing seems coming on this port
simply best solution, in my opinion
Glad you found it useful 🙂
Hi! Are you trying to run those few projects at the same time? If that's the case, it's possible that by default they will try to use that same port. Normally you can set
PORTas an env variable to tell the project to run that specified port (this depends on the server being used). You can try runningPORT=3001 npm start(or an equivalent to set env variables per command in your OS), changing the port value for each projectHi
Thanks for the reply. Actually now while running the project if I change the port number then it runs !
Thank you for your help :)
actually, you still didn't solve you problem, think how could you have been solved with changing the port, you should figure out, I am also facing same issue, but I also don't want to restart it and nor want to change the port
I was wondering if there is any way to define the port number in the source code ? For example if I want to set a different port number for different project ?
It really depends on the server and implementation being used. For example if the project is using
create-react-app, you can create a .env file with all your project based env variables. This is becausecreate-react-appuses dotenv. If you can find this out or you're able to share the github repo I may be able to assist furtherI just downloaded the projects form github randomly. couldn't find the repository URL. Do you know in which file of the source code the port number is defined ?
That also depends on the server being used. You can check the
package.jsonfile for more info, for example thescriptspart. What is the value for thestartcommand?I will check that . you are very helpful . Thanks a lot :)
Sometimes the Node process just hangs and you need to stop it manually.
Enter this into your terminal if you want to check if something is still running at that port:
lsof -i :3000Then you can stop the process in your terminal if you want.
tried that command but didn't worked
Hi! I used to encounter this error. It may happen if you close the editor or console with running
node— sometimes editor doesn't close it. You may use your console or process explorer to find it and forcibly stop freeing the port.Can you help for this, how can I check in console what is running on port 3000 and how can I forcibly stop it any command for MAC, I am new MAC user
I already checked running this command lsof -i :3000 seems noting is running on 3000, but still get the same error
Try running the same in
sudomodeIn Linux you can see localhost ports working in background by typing
jobscommand.Then you can kill the port by
kill -kill <job number>eg:
kill -kill %1Cảm ơn bạn rất nhiều
I'm in VietNamese