Lazy-loading images with suspense in React

16 Oct 2023

React is a popular JavaScript library for building user interfaces, and one common task in web development is lazy-loading images. Lazy-loading helps improve the performance of your web application by loading images only when they are needed, rather than all at once.

Traditionally, lazy-loading images in React involved using a third-party library or writing custom code. However, with the introduction of React Suspense, lazy-loading images has become much simpler and more seamless.

What is React Suspense?

React Suspense is a feature introduced in React 16.6 that allows you to handle components that are not yet ready. It provides a way to suspend rendering a component until some asynchronous operation, such as fetching data or loading an image, completes.

How to lazy-load images with suspense in React

To lazy-load images with suspense in React, you can follow these steps:

Import the Suspense and lazy components from the react library:

import React, { Suspense, lazy } from 'react';

Create a lazy component that imports the image component using the lazy function:

const LazyImage = lazy(() => import('./Image'));

Inside your component, wrap the lazy-loaded image component with the Suspense component and provide a fallback component to render while the image is being loaded:

<Suspense fallback={<div>Loading Image...</div>}>
  <LazyImage />
</Suspense>

Create the Image component and add the necessary logic to load the image:

import React, { useEffect, useState } from 'react';

const Image = () => {
  const [src, setSrc] = useState(null);

  useEffect(() => {
    const loadImage = async () => {
      const response = await fetch('https://example.com/my-image.jpg');
      const blob = await response.blob();
      const objectURL = URL.createObjectURL(blob);
      setSrc(objectURL);
    };

    loadImage();
  }, []);

  return <img src={src} alt="Lazy-loaded Image" />;
};

export default Image;

In the above example, we use the useEffect hook to load the image asynchronously using the fetch API. Once the image has been loaded, we set the src state to the object URL of the image blob.

That’s it! Now, when the component is rendered, the lazy-loaded image component will be suspended until the image is loaded. While it’s loading, the fallback component will be shown.

Benefits of lazy-loading images with suspense

Using suspense to lazy-load images in React has several benefits:

Improved performance: By loading images only when they are needed, you can reduce the initial load time of your web application and improve the overall performance.
Simplified code: The use of React Suspense simplifies the process of lazy-loading images by providing a seamless way to suspend rendering until the image is loaded.
Better user experience: With lazy-loading, images will only appear once they are fully loaded, improving the user experience and preventing broken or partially loaded images.

Conclusion

Lazy-loading images with suspense in React is a powerful technique that can significantly improve the performance of your web application. React Suspense provides a simple and elegant way to handle the asynchronous loading of images, making your code more efficient and your users’ experience smoother.

By incorporating lazy-loading into your React applications, you can enhance the user experience and reduce unnecessary network requests, leading to faster page load times. Give it a try in your next React project and see the difference it can make!

#react #webdevelopment