Advanced PWA Performance Topic 15: PWA Performance Best Practices

1. Introduction

Progressive Web Apps (PWAs) are designed to deliver a native app-like experience while being accessible via the web. Performance is critical for user satisfaction, engagement, and SEO. This lesson outlines advanced performance best practices for PWAs.

2. Performance Metrics

Understanding how to measure performance is essential. Key metrics to consider include:

• First Contentful Paint (FCP)
• Time to Interactive (TTI)
• Speed Index
• Cumulative Layout Shift (CLS)
• Time to First Byte (TTFB)

3. Best Practices

            <img src="image.webp" loading="lazy" alt="Description">
            

            <style>
            body { margin: 0; font-family: Arial, sans-serif; }
            </style>
            

            // Registering a Service Worker
            if ('serviceWorker' in navigator) {
                window.addEventListener('load', () => {
                    navigator.serviceWorker.register('/sw.js').then((registration) => {
                        console.log('ServiceWorker registration successful with scope: ', registration.scope);
                    }).catch((error) => {
                        console.log('ServiceWorker registration failed: ', error);
                    });
                });
            }
            

            @media (max-width: 600px) {
                body {
                    background-color: lightblue;
                }
            }
            

            // Run Lighthouse as a CLI command
            lighthouse https://your-pwa-url.com --output html --output-path ./report.html
            

4. FAQ