Implementing Video Lazy Loading

Introduction

In modern web development, lazy loading is an essential technique that optimizes resource loading to improve website performance and user experience. This lesson focuses on implementing lazy loading specifically for videos.

What is Lazy Loading?

Lazy loading is a design pattern that postpones the loading of non-essential resources at the point of page load. Instead of loading all videos immediately, lazy loading allows them to load only when they are about to enter the viewport, significantly reducing initial load time.

Benefits of Video Lazy Loading

Improves page load speed and performance.
Reduces bandwidth consumption by loading videos only when necessary.
Enhances user experience by providing faster access to the content that matters.
Decreases server load and improves scaling efficiency.

Implementation Steps

To implement video lazy loading, follow these steps:

Use the loading attribute: Use the native lazy loading feature available in HTML5 by adding the `loading="lazy"` attribute to your video element.
```
<video loading="lazy" src="video.mp4" controls></video>
```

Use Intersection Observer API: If you want more control, use the Intersection Observer API to detect when a video enters the viewport.

const videos = document.querySelectorAll('video');

                    const options = {
                        root: null,
                        rootMargin: '0px',
                        threshold: 0.1
                    };

                    const observer = new IntersectionObserver((entries, observer) => {
                        entries.forEach(entry => {
                            if (entry.isIntersecting) {
                                const video = entry.target;
                                video.src = video.dataset.src;
                                video.load();
                                observer.unobserve(video);
                            }
                        });
                    }, options);

                    videos.forEach(video => {
                        observer.observe(video);
                    });

Fallback for Unsupported Browsers: Implement a fallback for browsers that do not support lazy loading.
```
<video src="video.mp4" controls></video> 
```