How do you show skeleton loaders in Next.js?

Skeleton loaders are a popular UI pattern used to indicate that content is loading. They provide a placeholder that mimics the layout of the content that will eventually be displayed, enhancing the user experience by reducing perceived loading times. In a Next.js application, implementing skeleton loaders can be achieved through various methods, including using CSS, libraries, or custom components. Below, I will outline the steps to create skeleton loaders, best practices, and common mistakes to avoid.

Creating Skeleton Loaders in Next.js

To create skeleton loaders in a Next.js application, you can follow these steps:

1. Basic Skeleton Loader with CSS

One of the simplest ways to implement a skeleton loader is by using CSS. You can create a skeleton loader component that uses CSS animations to simulate loading.

import React from 'react';
import styles from './SkeletonLoader.module.css';

const SkeletonLoader = () => {
    return (
        

            

            

            

        
    );
};

export default SkeletonLoader;

In your CSS file (SkeletonLoader.module.css), you can define the styles:

.skeleton {
    padding: 20px;
    background: #e0e0e0;
    border-radius: 4px;
}

.title {
    width: 60%;
    height: 20px;
    background: #c0c0c0;
    margin-bottom: 10px;
    animation: pulse 1.5s infinite;
}

.line {
    width: 100%;
    height: 10px;
    background: #c0c0c0;
    margin-bottom: 5px;
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
    100% {
        opacity: 1;
    }
}

2. Using a Library

For more complex applications, you might want to use a library like react-content-loader. This library provides a set of customizable SVG-based skeleton loaders.

import React from 'react';
import ContentLoader from 'react-content-loader';

const MyLoader = () => (
    
         
         
         
    
);

export default MyLoader;

Best Practices

• Match the Layout: Ensure that the skeleton loader closely resembles the layout of the actual content to avoid confusion.
• Use Appropriate Timing: Display skeleton loaders only when the loading time exceeds a certain threshold (e.g., 200ms).
• Accessibility: Ensure that skeleton loaders are accessible by providing appropriate ARIA roles or using screen reader announcements.

Common Mistakes

• Overusing Skeleton Loaders: Using skeleton loaders for every loading state can lead to a cluttered UI. Use them judiciously.
• Ignoring Performance: Ensure that the skeleton loader does not add significant overhead to your application’s performance.
• Not Testing Responsiveness: Always test skeleton loaders on different screen sizes to ensure they adapt well.

By following these guidelines, you can effectively implement skeleton loaders in your Next.js application, improving the user experience during content loading.