What Is Route-Based Code Splitting in React.js?

Route-based code splitting in React.js involves splitting your application's code based on different routes or pages. This technique allows you to load only the code that is necessary for a specific route, resulting in faster initial loading times and improved performance. This is particularly beneficial for large applications with multiple routes, as it ensures that users only download the code required for the page they are currently viewing.

To implement route-based code splitting in React.js, you can use dynamic imports along with React Router, a popular routing library for React. Here's how you can achieve route-based code splitting:

Install React Router

If you haven't already installed React Router, you can do so using npm or yarn.

​​​​​​​npm install react-router-dom

Split Components

Identify the components that correspond to different routes in your application. These are the components that you want to split into separate bundles.

Dynamic Import

Use dynamic imports to lazily load the components associated with each route. This ensures that the code for each route is only loaded when the route is accessed by the user.

Here's an example:

import React, { Suspense, lazy } from 'react';
import { BrowserRouter as Router, Route, Switch } from 'react-router-dom';

const Home = lazy(() => import('./Home'));
const About = lazy(() => import('./About'));
const Contact = lazy(() => import('./Contact'));

function App() {
  return (
    <Router>
      <Suspense fallback={<div>Loading...</div>}>
        <Switch>
          <Route exact path="/" component={Home} />
          <Route path="/about" component={About} />
          <Route path="/contact" component={Contact} />
        </Switch>
      </Suspense>
    </Router>
  );
}

export default App;

In this example

1. The Home, About, and Contact components are imported lazily using dynamic imports. This means that each component will be loaded only when its corresponding route is accessed.
2. Suspense and Fallback: Wrap the Switch component with a Suspense component and provide a fallback UI to display while the component is loading. This ensures a smooth user experience by showing a loading indicator until the component is fully loaded.

By following these steps, you can implement route-based code splitting in your React.js application, resulting in improved performance and faster loading times for your users.