Lazy loading images checker

Free Lazy Loading Images Checker — Are Your Images Deferred?

This tool checks whether a page's images use the lazy-loading attribute. Enter any URL and you'll see which images are set to load lazily and which load immediately — a quick way to confirm one of the most effective image-performance techniques is in place.

Lazy loading defers off-screen images until the user scrolls near them, so the browser doesn't waste bandwidth and time fetching images nobody has reached yet. On image-heavy or long pages, this meaningfully speeds up the initial load and improves Core Web Vitals. Modern browsers support it natively with a simple loading="lazy" attribute — no JavaScript library required. Done right, it's a free speed win that benefits every visitor, especially on mobile.

There's one critical caveat this tool helps you catch: never lazy-load your LCP image — the large hero or first above-the-fold image. Adding loading="lazy" to everything, including that one, actually delays Largest Contentful Paint and hurts your score. The correct pattern is to lazy-load below-the-fold images while letting (or even preloading) the above-the-fold ones load eagerly. Use this tool to confirm your below-the-fold images are deferred and that your hero image is not — the combination that gives you the speed benefit without the LCP penalty.

From one check to a complete audit

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