Lazy loading demystified

What Lazy Loading Is

Lazy loading delays the download of resources—such as images, videos, iframes, or widgets—until they are needed, instead of fetching everything at once.

Advantages

• Reduces bandwidth and network usage.
• Preserves device resources like CPU and battery.
• Speeds up websites, particularly long pages or those viewed on mobile devices.

Advantages

• Native HTML support with loading=”lazy” for images and iframes is generally reliable.
• Custom JavaScript lazy loading can block indexing if the src attribute is missing or misused.
• Incorrect setup can negatively affect Core Web Vitals, especially Largest Contentful Paint (LCP).

SEO Considerations

• Native HTML support with loading=”lazy” for images and iframes is generally reliable.
• Custom JavaScript lazy loading can block indexing if the src attribute is missing or misused.
• Incorrect setup can negatively affect Core Web Vitals, especially Largest Contentful Paint (LCP).

Best Practices and Risks

• Avoid applying lazy loading to critical images (e.g., hero images above the fold).
• Ensure the final rendered HTML exposes image URLs properly so Googlebot can crawl them.

How to Verify Implementation

• Use Google Search Console’s URL Inspection Tool to confirm that lazy-loaded elements are visible in the rendered HTML.
• Check whether important images appear in Google Images.

Comparison to Infinite Scroll

• Both techniques load content progressively.
• Lazy loading defers secondary elements on the same page, while infinite scroll continuously appends new content.

you can safeguard your site’s SEO performance, preserve rankings, and maintain visibility with minimal impact.