Native loading=lazy vs ad-script lazy loading

Native loading=lazy vs ad-script lazy loading

What it does — both delay loading until near viewport. loading="lazy" is a browser attribute for images/iframes; ad-script lazy loading uses IntersectionObserver to defer the ad request itself.

Setup effort (1-5) — Native: 1 (one attribute). Script: 3 (observer, rootMargin tuning, fallback).

RPM lift seen — Native on the ad iframe: looks free but often hurts, you defer the request too late and lose the impression. Script-based with a 200px rootMargin: +5-9% RPM via better viewability without losing fill.

Pros / Cons —
Native: trivial, but you don't control when the auction fires, so below-fold units underdeliver.
Script: precise timing control, recovers the impression before scroll arrives, but more to maintain.

Verdict — Never put native lazy on monetized iframes. Use IntersectionObserver with rootMargin so the request fires early. Native lazy is for content images only.

Lift: ★★★☆☆ — Risk: ★★☆☆☆
Best for: long-scroll layouts. Skip if all units are above the fold.