What Is Lazy Loading And How Does It Help CMS Performance?
BeginnerQuick Answer
TL;DR
Lazy loading defers the loading of non-critical resources — images, videos, iframes, and below-the-fold content — until they are needed, typically when they scroll into the viewport. This reduces initial page load time, saves bandwidth for users who never scroll to certain content, and improves Core Web Vitals scores. The browser's native `loading="lazy"` attribute handles most image and iframe cases without any JavaScript.
Key Takeaways
- The HTML `loading="lazy"` attribute is supported in all modern browsers and requires no JavaScript or plugins
- Lazy loading images directly improves Largest Contentful Paint (LCP) and reduces Total Blocking Time on content-heavy CMS pages
- Low-quality image placeholders (LQIP) prevent layout shift while full images load, protecting Cumulative Layout Shift (CLS) scores
- WordPress supports native lazy loading for images by default since version 5.5
- Lazy loading JavaScript modules and below-the-fold components reduces initial bundle size and speeds up Time to Interactive