Performance
PerformanceLow

Below-Fold Lazy Loading

Checks below-the-fold images and iframes use loading="lazy".

What this check measures

We count images and iframes below the initial viewport. Each should use `loading="lazy"` to defer loading until near the viewport.

Why it matters

Lazy-loading below-the-fold cuts initial page weight 50-80% on image-heavy pages. LCP improves, data usage drops, battery life improves on mobile.

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How our audit detects it

Heuristically identify below-the-fold images (based on DOM position). Check for loading="lazy" attribute.

Typical findings

  • error_outlineAll 40 product thumbnails load eagerly.
  • error_outlineYouTube iframe below fold without loading="lazy".

How to fix

Add `loading="lazy"` to every below-the-fold image and iframe. NEVER on the LCP element. Native support is universal in 2026.

Frequently asked questions

Lazy all images?expand_more
No — above-the-fold / LCP image must be eager. Lazy breaks LCP timing.

Want this checked on your site?

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