In a recent episode of Google’s Search Off the Record podcast, developer advocate Martin Splitt cautioned webmasters against a common performance pitfall — applying lazy loading to every image on a page, including those above the fold.
Splitt revealed that even Google’s own developers’ site once defaulted all images to lazy loading, a choice that “is not great” when it includes the hero image.
By telling the browser to delay fetching the most prominent visual element, sites risk pushing back their Largest Contentful Paint (LCP) — a key Core Web Vitals metric — and creating a jarring experience if image dimensions aren’t set.
Why It Matters for LCP
LCP measures how quickly the largest visible element (often a hero image) renders in the initial viewport.
Normally, browsers prioritize this asset early. But when loading=”lazy” is applied, the browser treats it as low priority, fetching it only after layout and other resources are processed.
On slower networks or devices, this delay becomes more pronounced, and missing width/height attributes can cause layout shifts.
SEO & Indexing Risks
Splitt also warned about older or custom lazy-loading scripts that hide image URLs in nonstandard attributes like data-src.
If Google’s rendering engine doesn’t see a valid src or srcset in the final HTML, those images may not be indexed at all.
Best Practices Moving Forward
- Eager-load above-the-fold images — especially the hero — and set explicit width and height.
- Use native loading=”lazy” for below-the-fold images and iframes.
- Verify in Search Console’s URL Inspection that rendered HTML contains proper src attributes for all images.
- Treat lazy loading as an opt-in for noncritical content, not a blanket setting.
While Splitt noted that Core Web Vitals are only a “tiny minute factor” in rankings, poor LCP can still hurt user experience and engagement.
For publishers, especially those chasing Google News and Discover visibility, shaving milliseconds off LCP could mean the difference between a bounce and a loyal reader.
You can catch the full discussion in Google’s Search Off the Record episode featuring Martin Splitt and John Mueller on lazy loading and LCP — it’s available on Google’s official podcast page and also as a YouTube version if you prefer to watch.