1. Introduction

1.1 Tutorial's goal

This tutorial aims to provide you with practical and effective strategies for optimizing the performance of your Nuxt.js applications.

1.2 Learning Outcomes

By the end of this tutorial, you will be able to:
- Understand how to analyze your Nuxt.js application's performance.
- Implement several performance optimization techniques.
- Write cleaner and more efficient code.

1.3 Prerequisites

Before proceeding with this tutorial, you should have a basic understanding of:
- JavaScript (ES6)
- Vue.js and Nuxt.js
- Node.js and npm/yarn

2. Step-by-Step Guide

2.1 Server-side Rendering (SSR) optimization

Nuxt.js uses SSR to provide better SEO and faster initial page loading. However, SSR can be CPU-intensive. Therefore, we can use caching to reduce the load.

// In your nuxt.config.js
export default {
  render: {
    ssrLog: true,
    http2: {
      push: true
    },
    bundleRenderer: {
      shouldPreload: (file, type) => ['script', 'style', 'font'].includes(type),
      cache: require('lru-cache')({
        max: 1000,
        maxAge: 1000 * 60 * 15
      })
    }
  }
}

2.2 Build optimization

When building your Nuxt.js application, you can analyze your bundles to find which parts are taking up the most space.

// In your nuxt.config.js
export default {
  build: {
    analyze: true,
    optimization: {
      splitChunks: {
        chunks: 'all',
        automaticNameDelimiter: '.',
        name: undefined,
        cacheGroups: {},
      }
    },
  },
}

3. Code Examples

3.1 Code Splitting

You can split your code into various bundles so that the browser only loads what's needed when it's needed.

// Example of dynamic imports in Nuxt.js
const HomePage = () => import('~/pages/home.vue')

3.2 Lazy Loading

You can also implement lazy loading for your images and components to improve the perceived load time.

// Lazy load images with v-lazy-image Vue component
<v-lazy-image src="path-to-your-image.jpg"></v-lazy-image>

4. Summary

In this tutorial, we have covered the basics of performance tuning in Nuxt.js applications. We've learned how to optimize SSR, build processes, implement code splitting, and lazy load resources.

5. Practice Exercises

1. Exercise 1: Implement a caching mechanism for your SSR Nuxt.js application.
2. Exercise 2: Use bundle analyzer to identify large dependencies and find ways to optimize them.
3. Exercise 3: Implement code splitting and lazy loading in your Nuxt.js application.

Solutions

1. Solution to Exercise 1

Implementing caching for SSR in Nuxt.js can be done using the render property in nuxt.config.js.

2. Solution to Exercise 2

After enabling the analyze flag in nuxt.config.js, you can run npm run build --analyze to see a visual representation of your bundles.

3. Solution to Exercise 3

You can use dynamic imports to split your code and the v-lazy-image component to lazily load your images.

Further Practice

Try to implement these optimization techniques in a Nuxt.js application and monitor the changes in performance using tools like Google's Lighthouse.