What Is Lazy Loading?
Lazy loading is a technique where non-critical resources—usually images, iframes, or videos—are only loaded when they enter (or are about to enter) the user’s viewport. Instead of loading everything at once when the page loads, lazy loading delays resource delivery until needed. The result? Faster initial render, smaller page weight, better Core Web Vitals, and a smoother user experience—especially on mobile. For SEO, it means lower bounce rates and higher engagement, two indirect signals that Google loves.
Where It Helps Most (and Where to Be Careful)
Lazy loading is most effective for below-the-fold images, third-party embeds (like YouTube videos), social media widgets, maps, and long content pages. Use it for blog post thumbnails, ecommerce product grids, and portfolio galleries. Be cautious with critical visuals—above-the-fold images should be preloaded or excluded from lazy loading to avoid layout shifts. Also, ensure lazy-loaded content still appears in your raw HTML or is rendered early enough that crawlers don’t miss it.
Modern browsers support native lazy loading with `loading="lazy"` on `` and `