Lazy Loading: Boost Performance by Loading Content On-Demand

What is Lazy Loading?

Lazy loading is a technique that delays loading non-critical resources until they're needed. Instead of loading all images when the page loads, lazy loading only loads images when they enter the viewport.

Benefits of Lazy Loading

Faster initial load: Less data to download

Reduced bandwidth: Only load what users see

Better LCP: Critical content loads first

Lower costs: Less server bandwidth used

Native Lazy Loading

Modern browsers support native lazy loading with a simple attribute:

``html

`

Browser Support

Chrome 77+

Firefox 75+

Safari 15.4+

Edge 79+

Best Practices

Don't Lazy Load Above-the-Fold

Images visible on initial load should NOT be lazy loaded:

`html

`

Provide Dimensions

Always include width and height to prevent layout shifts:

`html

loading="lazy"

width="800"

height="600"

alt="Description">

`

Use Placeholder Colors

Show a placeholder while the image loads:

`css

img[loading="lazy"] {

background: #f0f0f0;

}

``

What We Check

Our Lazy Loading Audit analyzes:

Image loading attributes: Proper lazy loading implementation

Above-the-fold detection: Hero images shouldn't be lazy

Dimension attributes: Width and height presence

JavaScript fallbacks: For older browsers

Audit your lazy loading implementation with our free performance tool.