Hello everyone,

In this short blog post , I will be writing about how we can override the default port number in Next.js application.

Why am I writing this ?

Today when I was working I had to run two different Next.js application say app A and app B . Since the default port of Next.js application was 3000 and I was not able to run app B .

Immediately went online searching for how to change port , it was simple one.

let's dive in

How do we change it ?

let's assume that you have Next.js app bootstrapped using manual configuration or using create-next-app .

Go to package.json file of your Next.js app and do the following

Note: Following is the package.json from my side project which I have been working on.

{
  "name": "front-end",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "dev": "next dev", 
    "build": "next build",
    "start": "next start",
    "lint": "next lint"
  },
  "dependencies": {
    "@chakra-ui/icons": "1.1.0",
    "@chakra-ui/react": "1.7.0",
    "@emotion/react": "11.5.0",
    "@emotion/styled": "11.3.0",
    "axios": "0.24.0",
    "framer-motion": "5.0.0",
    "next": "12.0.3",
    "nookies": "2.5.2",
    "react": "17.0.2",
    "react-dom": "17.0.2",
    "react-icons": "^4.3.1"
  },
  "devDependencies": {
    "@types/react": "17.0.34",
    "eslint": "8.0.1",
    "eslint-config-next": "12.0.3",
    "typescript": "4.4.4"
  }
}

to

{
  "name": "front-end",
  "version": "0.1.0",
  "private": true,
  "scripts": {
    "dev": "next dev -p 3001",
    "build": "next build",
    "start": "next start",
    "lint": "next lint"
  },
  "dependencies": {
    "@chakra-ui/icons": "1.1.0",
    "@chakra-ui/react": "1.7.0",
    "@emotion/react": "11.5.0",
    "@emotion/styled": "11.3.0",
    "axios": "0.24.0",
    "framer-motion": "5.0.0",
    "next": "12.0.3",
    "nookies": "2.5.2",
    "react": "17.0.2",
    "react-dom": "17.0.2",
    "react-icons": "^4.3.1"
  },
  "devDependencies": {
    "@types/react": "17.0.34",
    "eslint": "8.0.1",
    "eslint-config-next": "12.0.3",
    "typescript": "4.4.4"
  }
}

Based on the above code, only change which has to be made is to add -p in next dev with port number at the end.

"dev": "next dev -p 3001"

Now go to your terminal and run yarn run dev your second Next.js application should be running on port 3001. Go to http://localhost:3001 url to see the app live on your local machine.

Conclusion:

That's pretty much it. Thank you for taking the time to read the blog post. If you found the post useful , add ❤️ to it and let me know if I have missed something in the comments section. Feedback on the blog are most welcome.

Let's connect on twitter : (https://twitter.com/karthik_coder)