Above the fold image (<srcset> example)

Lazy loading <img> with srcset

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Lazy loading <img> using src

Lazy loading <img> with src

Lazy loading <img> using srcset

Lazy loading <img> with srcset

Lazy loading SVG

Lazy loading <img> with src

Lazy loading <picture>

Lazy loading <img> with src

Lazy loading <video> (autoplay/GIF-like behavior)

Lazy loading <video> (No autoplay, lazy load poster image)

Lazy loading <iframe>

Lazy loading CSS background images: