Performance & Core Web Vitals · Glossary term

Lazy loading explained without jargon.

Technique for loading images / iframes only when the user reaches them (scroll). Reduces LCP + bandwidth.

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Extended definition

Technique for loading images / iframes only when the user reaches them (scroll). Reduces LCP + bandwidth.

Context and application

Native lazy loading (loading="lazy") is supported in all modern browsers since 2020. Apply on ALL images EXCEPT those above-the-fold (LCP image — on those put loading="eager" and fetchpriority="high"). Apply also on iframes (YouTube embeds, Google Maps, Twitter cards). Common mistake: lazy loading on hero image — delays LCP by 1-2 seconds and breaks ranking. For complete content management, plugins like Smush, ShortPixel, or LiteSpeed Cache automate.

In practice

loading="lazy" attribute on below-fold images.

Related terms

Image optimization, Core Web Vitals.

Rest of the glossary

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