Question 1

How to lazy load background images with Lozad.js?

Accepted Answer

Add the lozad class to elements and use data-background-image for single images or data-background-image-set for responsive sets; for multiple images, customize the delimiter with data-background-delimiter.

Question 2

Lozad.js vs native lazy loading: which should I use?

Accepted Answer

Native lazy loading is simpler for basic img and iframe tags in modern browsers, but Lozad.js offers more control, supports wider media types like videos and background images, and handles dynamic content better.

Question 3

Does Lozad.js work with React or Vue?

Accepted Answer

Yes, but it requires manual integration since it's vanilla JavaScript; you'll need to call observe() on component mount and manage state changes, unlike framework-specific lazy loaders.

Question 4

What polyfills are needed for older browsers?

Accepted Answer

For IE11 and unsupported browsers, you must include polyfills for IntersectionObserver and Object.assign, as noted in the README's browser support section.

Question 5

How to handle slow-loading images with Lozad.js?

Accepted Answer

Use the data-placeholder-background attribute to set a temporary background color, improving perceived performance while the image loads, as described in the 'Large image improvement' section.

Question 6

Can Lozad.js lazy load videos and iframes?

Accepted Answer

Yes, apply the lozad class to video tags with data-poster for thumbnails or iframe tags with data-src, and it will defer loading until they enter the viewport.

Lozad.js

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