React vs Next.js

React is a library for building user interfaces. It focuses on creating components, managing state, and updating the UI when data changes. With React alone, you are responsible for setting up everything else, such as routing, data fetching, and project structure.

Next.js builds on top of React and provides these features out of the box. It gives you a clear way to organize your application, handle navigation between pages, and run code on both the server and the client.

Instead of combining multiple libraries and configuring them manually, Next.js offers a complete environment for building modern web applications.

Example - React App vs Next.js App

In a typical React setup, you often need additional libraries:

import { BrowserRouter, Routes, Route } from "react-router-dom";
import Home from "./Home";
import About from "./About";

function App() {
  return (
    <BrowserRouter>
      <Routes>
        <Route path="/" element={<Home />} />
        <Route path="/about" element={<About />} />
      </Routes>
    </BrowserRouter>
  );
}

You must install and configure a routing library to handle navigation.

In Next.js, routing is handled automatically using the file structure:

app/
  page.js
  about/
    page.js

Each file becomes a route without additional configuration.

Key Differences

• React is a library focused on UI;
• Next.js is a framework built on top of React;
• React requires additional setup for routing and data handling;
• Next.js provides routing and structure by default;
• Next.js allows running code on the server and the client.

When to Use Each

React is useful when you want full control over how your application is structured and which tools you use.

Next.js is a better choice when you want to build a complete web application faster, with built-in routing, data handling, and performance optimizations.

Next.js does not replace React. It extends it and provides a more structured way to build real-world applications.