Script: next dev vs next build vs next start

In Next.js, next dev is used to run the app in development mode. On the other hand, `next start` is used to run the app in production mode, but requires `next build` to be run first to generate an optimized production build.

Development

When running the Next.js app in development, you'll want to use `next dev`:

next dev starts the application in development mode with hot-code reloading, error reporting, and more.

Production

When building the Next.js app for production, you'll want to use `next build`:

next build creates an optimized production build of your application. The output displays information about each route.

• Size – The number of assets downloaded when navigating to the page client-side. The size for each route only includes its dependencies.
• First Load JS – The number of assets downloaded when visiting the page from the server. The amount of JS shared by all is shown as a separate metric.

Followed by either next start, when you want to start the production server:

next start starts the application in production mode. The application should be compiled with `next build` first.

{
  "scripts": {
    "dev": "next dev",
    "build": "next build",
    "start": "next start"
  },
}