Introduction to Lazy Loading

What is Lazy Loading?

Lazy loading is a design pattern that postpones the loading of non-essential resources at the point the page is initially loaded. This technique is primarily used to improve the performance of web applications, resulting in faster initial loading times and improved user experience.

Benefits of Lazy Loading

How to Implement Lazy Loading

Implementing lazy loading can be accomplished with various techniques. Below is a basic example using the native HTML loading attribute and JavaScript:

<img src="image.jpg" loading="lazy" alt="Lazy Loaded Image">

JavaScript Method

If you need more control or want to support older browsers, you can use JavaScript:

const lazyLoadImages = document.querySelectorAll('img[data-src]');
            const imageObserver = new IntersectionObserver((entries, observer) => {
                entries.forEach(entry => {
                    if (entry.isIntersecting) {
                        const img = entry.target;
                        img.src = img.dataset.src;
                        img.classList.remove('lazy');
                        observer.unobserve(img);
                    }
                });
            });

            lazyLoadImages.forEach(image => {
                imageObserver.observe(image);
            });

Best Practices

• Use the loading="lazy" attribute for images whenever possible.
• Implement intersection observers for custom lazy loading.
• Test your implementation across different devices and browsers.
• Monitor performance metrics to analyze the impact of lazy loading.

FAQ