What is code splitting in a React application?

TL;DR

Code splitting in a React application is a technique used to improve performance by splitting the code into smaller chunks that can be loaded on demand. This helps in reducing the initial load time of the application. You can achieve code splitting using dynamic import() statements or React's React.lazy and Suspense.

// Using React.lazy and Suspense
const LazyComponent = React.lazy(() => import('./LazyComponent'));

function App() {
  return (
    <React.Suspense fallback={<div>Loading...</div>}>
      <LazyComponent />
    </React.Suspense>
  );
}

What is code splitting in a React application?

Introduction

Code splitting is a performance optimization technique that involves breaking down your application's code into smaller, more manageable chunks. This allows the application to load only the necessary code initially and defer the loading of other parts until they are needed. This can significantly reduce the initial load time and improve the overall user experience.

How to implement code splitting

Using dynamic `import()`

Dynamic import() is a JavaScript feature that allows you to load modules asynchronously. This can be used to split your code into separate chunks.

// Dynamic import example
import('./module').then(module => {
  // Use the module
});

Using React.lazy and Suspense

React provides built-in support for code splitting through React.lazy and Suspense. React.lazy allows you to render a dynamic import as a regular component, and Suspense lets you specify a loading fallback while the component is being loaded.

// Lazy loading a component
const LazyComponent = React.lazy(() => import('./LazyComponent'));

function App() {
  return (
    <React.Suspense fallback={<div>Loading...</div>}>
      <LazyComponent />
    </React.Suspense>
  );
}

Benefits of code splitting

Improved performance: By loading only the necessary code initially, you can reduce the initial load time of your application.
Better user experience: Faster load times lead to a smoother and more responsive user experience.
Efficient resource usage: Code splitting ensures that resources are used more efficiently by loading code only when it is needed.

Tools and libraries

Webpack: Webpack is a popular module bundler that supports code splitting out of the box. You can configure it to split your code into chunks automatically.
React Loadable: Although React.lazy and Suspense are the recommended ways to implement code splitting in React, React Loadable is an older library that also provides similar functionality.

What is code splitting in a React application?

TL;DR