Is it true that native lazy loading is crawled by Googlebot?

What is native lazy loading and why does this statement matter?

Native lazy loading relies on the HTML attribute loading='lazy' introduced in modern browsers. This attribute delays image loading until they approach the user's viewport, thereby reducing the initial weight of the page and improving Core Web Vitals.

Before this announcement, many SEOs wondered if Googlebot — which doesn’t scroll like a human — could discover these deferred images. Martin Splitt's official response clears up some ambiguity: Googlebot understands this attribute and knows it must load these resources to properly index visual content.

How does Googlebot treat a page with native lazy loading?

Googlebot uses a headless version of Chromium, the Chrome engine. This version adheres to web standards, including the native behavior of the loading='lazy' attribute.

The bot starts by loading the initial viewport. If images have this attribute and are outside the viewport, it still triggers their loading during the JavaScript rendering phase. Unlike a custom lazy loading script that requires simulated scrolling, native lazy loading is automatically interpreted by the rendering engine.

However, beware: Googlebot does not perform endless scrolling. If a lazy image is too far down the page or depends on a complex user event, it may not be discovered.

What is the impact on image indexing?

Images with native lazy loading can be indexed in Google Images if they are accessible during rendering. This is an improvement over old JS libraries that sometimes blocked crawling.

That said, the indexing of an image also depends on its relevance, alt tags, the semantic context around it, and its perceived quality. Native lazy loading facilitates technical discovery but does not guarantee a high ranking in image results.

• Googlebot supports the loading='lazy' attribute: no need to worry that your lazy images won't be seen.
• Native lazy loading is less risky than poorly implemented custom JavaScript solutions.
• Images must remain accessible in the source HTML with a valid URL: no empty src replaced by JS.
• The initial viewport must contain sufficient content for Googlebot to trigger full rendering.
• Native lazy loading does not negatively impact SEO if well configured, but it does not exempt you from optimizing alt, title, and semantic context.

Is this statement consistent with field observations?

Yes, generally. Since Googlebot switched to headless Chromium, field reports show that pages using native lazy loading correctly index their images — provided the source HTML contains the actual URL in src or data-src recognized by the standard.

However, some tests indicate that if a page has dozens of lazy images far down in the DOM, not all may be crawled on the first pass. Googlebot has a limited render budget: it will not wait indefinitely for all lazy resources to load. [To be verified] on long pages with infinite scroll or complex progressive loading.

What nuances should be added to this statement?

Martin Splitt's statement remains generic. It does not specify whether Googlebot simulates a mobile or desktop viewport, nor how long it waits for lazy images to load before considering the page rendered.

Moreover, native lazy loading depends on the browser and its internal logic for loading thresholds. Chromium loads lazy images when they are at a certain distance from the viewport — a distance that can vary by version and connection. Does Googlebot follow this logic exactly? Probably, but without official data, it's reverse engineering.

Another point: this statement says nothing about lazy iframes or videos. One can assume that support extends to all native elements accepting the loading attribute, but this is not explicit.

In what cases does this rule not apply?

If you are using a custom JavaScript library for lazy loading that replaces src with data-src or another proprietary attribute, this statement does not directly apply to you. Googlebot will only understand these mechanisms if it executes your JS and it works well in a headless environment.

Similarly, if your lazy images depend on a user event — click, hover, infinite scroll via non-standard intersection observer — Googlebot may not detect them. Native lazy loading is passive: it automatically triggers on rendering. A script waiting for human action blocks the bot.

What practical steps should you take to leverage this statement?

Migrate to native lazy loading wherever possible. Replace your custom lazy loading scripts with the HTML attribute loading='lazy' on your <img> and <iframe> tags. It’s lighter, faster, and Googlebot understands it natively.

Ensure the src attribute always contains the actual URL of the image, never a placeholder or a generic data-URI. Native lazy loading delays network loading, but the browser must know the URL right from the start to schedule the request.

What mistakes should be avoided with native lazy loading?

Do not mark loading='lazy' on images in the initial viewport — those visible without scrolling. This unnecessarily delays their loading and degrades LCP (Largest Contentful Paint), a critical metric for Core Web Vitals.

Avoid lazy loading critical images for SEO: logo, hero image, key products. If an image carries significant SEO weight, load it normally or in preload to ensure its immediate discovery.

Be cautious with CMS or builders that automatically apply loading='lazy' to all images indiscriminately. Manually check strategic pages and adjust behavior if needed.

How can I verify that my native lazy loading is being crawled by Google?

Use the URL Inspection tool in Google Search Console. Request a live test, then check the "Screenshot" tab and "More info" > "Rendered HTML". Ensure that your lazy images appear in the final DOM and that their URLs are present.

Cross-reference with server logs: Googlebot should make HTTP requests to your images. If they do not appear in the logs while being in native lazy loading, this is a warning signal.

Also monitor the Coverage and Images reports in Search Console. If lazy images disappear from the index after migration, audit the source HTML code and behavior in headless.

• Switch to <img loading='lazy'> tags instead of custom JS scripts
• Always provide src with the actual URL, never a placeholder
• Never lazy load images in the initial viewport or those critical for LCP
• Test each strategic page with URL Inspection and check the rendering
• Cross-check with server logs to confirm that Googlebot is loading the images
• Regularly audit the Images report in Search Console