Development Workflow & CLI

Every Next.js project revolves around the same small set of CLI commands, provided by the next package itself. create-next-app wires them into package.json scripts for you, so day-to-day you run them through npm run rather than typing next directly.

The core commands

Command	What it does
`next dev`	Starts the local development server with Fast Refresh, detailed error overlays, and no production optimizations.
`next build`	Compiles an optimized production build — statically generating what it can, and preparing everything else to be rendered on demand.
`next start`	Serves the output of `next build` as a production Node.js server.
`next lint`	Runs ESLint using the `eslint-config-next` rule set tailored for Next.js projects.

The package.json convention

A scaffolded project wires each command up as an npm script, so you rarely type next directly:

package.json (scripts excerpt)

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

Bash

npm run dev     # develop locally
npm run build   # build for production
npm run start   # run the production build
npm run lint    # check for lint issues

Fast Refresh

While next dev is running, saving a file triggers Fast Refresh: edited components update in the browser almost instantly, and in most cases React component state is preserved across the edit — you do not lose your place in a form or a modal just because you tweaked some styling.

 ✓ Compiled /about in 87ms

Turbopack

Turbopack is a newer, Rust-based bundler built specifically for Next.js, designed to replace Webpack as the dev-server engine with significantly faster cold starts and incremental updates on large projects. You can opt into it explicitly:

Bash

next dev --turbo

Note

Turbopack's dev-server support has matured quickly across recent Next.js releases and became the default for `next dev` starting with Next.js 15.x in newer scaffolds, but production builds (`next build --turbo`) are still catching up. Check the release notes for the exact Next.js version you are using before relying on it in production.

next dev — local development with Fast Refresh.
next build — creates the optimized production build.
next start — serves that build as a Node.js server.
next lint — lints the project with Next.js-aware rules.