Increase ReactJS Efficiency: Implementing Code Splitting for Faster Performance

ReactJS, a popular JavaScript library for building user interfaces, is known for its efficiency and flexibility. However, as applications grow in size and complexity, the load times can become a concern. One effective technique to mitigate this issue is code splitting. This article explores how code splitting can improve component load speed in ReactJS applications.

Understanding Code Splitting

Code splitting is a process of breaking down a large bundle of JavaScript code into smaller chunks that can be loaded on demand. Instead of loading the entire application code at once, the application only loads the necessary code for the current user interaction. This results in faster initial load times and a more responsive user experience.

Benefits of Code Splitting

  1. Improved Performance: By loading only the required code, the initial load time decreases significantly, enhancing the application’s performance.
  2. Reduced Bundle Size: Smaller bundles mean less data to download, which is especially beneficial for users on slower networks.
  3. Enhanced User Experience: Faster load times and smoother interactions lead to a better user experience, encouraging longer engagement with the application.

Implementing Code Splitting in React

React provides built-in support for code splitting through dynamic import() syntax and React.lazy. Below are the steps to implement code splitting in a React application.

Step 1: Install React and Webpack

If you haven’t already, start by setting up a React application using Create React App, which comes pre-configured with Webpack:

npx create-react-app my-app
cd my-app
npm start

Step 2: Dynamic Import with React.lazy

React.lazy makes it easy to render a dynamic import as a regular component. Here’s how to use it:

  1. Create Components: Create two new components, Home.js and About.js.
    • // Home.js
      import React from 'react';

      const Home = () => {

      Home Component


      export default Home;

      // About.js
      import React from 'react';

      const About = () => {

      About Component


      export default About;

  2. Implement Lazy Loading: In your main component, use React.lazy to dynamically import these components.
    • // App.js
      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'));

      function App() {
      return (




export default App;

Step 3: Suspense Component

The Suspense component is used to wrap lazy-loaded components and provide a fallback UI (e.g., a loading spinner) while the component is being loaded.


Step 4: Optimizing with React Router

When using React Router, each route can be code-split into its own chunk. This way, only the necessary code for the route being visited is loaded.