How to Run a Next.js Project: Step-by-Step Guide

To run a Next.js project, first install dependencies with npm install or yarn. Then start the development server using npm run dev or yarn dev. This launches the app locally at http://localhost:3000.

Syntax

Running a Next.js project involves these main commands:

• Install dependencies: npm install or yarn downloads all required packages.
• Start development server: npm run dev or yarn dev launches the app locally.
• Build for production: npm run build or yarn build prepares optimized files.
• Start production server: npm start or yarn start runs the built app.

bash

npm install
npm run dev

Output

Local server started at http://localhost:3000

Example

This example shows how to run a fresh Next.js project after cloning or creating it.

First, open your terminal in the project folder and run the commands below.

bash

npm install
npm run dev

Output

ready - started server on http://localhost:3000
info  - Loaded env from .env.local
info  - Using webpack 5. Fast Refresh is enabled.

Common Pitfalls

Common mistakes when running Next.js projects include:

• Not installing dependencies before running npm run dev, causing errors.
• Running commands outside the project folder.
• Using outdated Node.js versions (Next.js requires Node.js 14.6 or newer).
• Port 3000 already in use, causing the server to fail to start.

Always check your terminal output for errors and fix them accordingly.

bash

Wrong:
npm run dev

Right:
npm install
npm run dev

Quick Reference

Summary of commands to run a Next.js project:

Command	Purpose
npm install	Install project dependencies
npm run dev	Start development server locally
npm run build	Build project for production
npm start	Run production server

Key Takeaways

Always run npm install or yarn before starting the server to install dependencies.

Use npm run dev or yarn dev to start the development server at http://localhost:3000.

Ensure your Node.js version is 14.6 or higher for compatibility.

Check for port conflicts if the server fails to start.

Use npm run build and npm start to run the project in production mode.