What is Lazy Loading?
Lazy loading is a technique used in web development to delay the loading of non-critical resources, such as images, videos, or iframes, until they are needed. Instead of loading all assets when the page initially loads, lazy loading loads content only when the user scrolls to it or interacts with it.
This is commonly used for image-heavy pages, long articles, or media galleries to improve performance and reduce initial page load time.
Why Lazy Loading Matters
Lazy loading helps improve user experience and website performance by reducing the amount of data that needs to be loaded upfront. It allows pages to load faster, especially on slower connections or mobile devices, and reduces the demand on servers.
Benefits of lazy loading include:
- Faster initial page loads
- Reduced bandwidth usage
- Improved performance on mobile devices
- Better Core Web Vitals scores (especially LCP)
- Enhanced SEO and user engagement
It is particularly valuable on long or media-rich pages where not all content is immediately visible.
Example in Use
On an online magazine, lazy loading can be used to delay the loading of embedded videos and article images until the user scrolls near them. This speeds up the initial load and ensures resources are used more efficiently.
In HTML, lazy loading is often implemented with the loading="lazy" attribute on image or iframe tags.
Related Terms
- Page Speed
- Core Web Vitals
- Image Optimization
- JavaScript
- Technical SEO