What are the best practices for lazy loading images on a website?

What are the best practices for lazy loading images on a website?

Lazy loading is a technique to delay loading images until they are needed. Here are some best practices: 1. Use the loading attribute in <img> tags. 2. Implement a placeholder image. 3. Use Intersection Observer API for better performance. 4. Ensure images are optimized for web.

Can you explain how the Intersection Observer API works?

Sure! The Intersection Observer API allows you to asynchronously observe changes in the intersection of a target element with an ancestor element or with a top-level document's viewport. This is useful for lazy loading because you can trigger the loading of images when they are about to enter the viewport.

What are some common mistakes to avoid when implementing lazy loading?

Common mistakes include: 1. Not providing a fallback for browsers that don't support lazy loading. 2. Overusing lazy loading on critical images, which can affect user experience. 3. Forgetting to optimize images, leading to slow loading times.

How can I test if lazy loading is working correctly on my site?

You can test lazy loading by using browser developer tools. Check the network tab to see if images are loaded only when they come into the viewport. You can also use performance testing tools to analyze loading times.