Google made Core Web Vitals an official ranking signal in 2021. Three years later, most Webflow sites still fail them.

The three metrics are LCP (Largest Contentful Paint), INP (Interaction to Next Paint, which replaced FID), and CLS (Cumulative Layout Shift). In plain terms: how fast does your main content load, how quickly does the page respond to input, and does the layout shift around while loading? These are things users feel even if they can't name them.

For Webflow sites, the failures tend to cluster around the same issues.

LCP failures usually come from large hero images. If your above-the-fold image isn't compressed and properly sized, it will be your LCP element — and it will be slow. In Webflow, set hero images to load eagerly (not lazy), use WebP format, and keep file sizes under 100kb where possible.

CLS failures in Webflow are often caused by embeds (YouTube videos, forms, third-party widgets) that don't have reserved space, or by web fonts loading after content and causing a layout shift. Add explicit height and width to embeds and use font-display: swap in your custom code.

INP failures are less common on Webflow sites but happen with heavy JavaScript interactions or large Webflow animations firing on click.

To check your scores, go to PageSpeed Insights and test your homepage and main landing pages. Aim for green on all three metrics on both mobile and desktop. The mobile score is what Google uses for indexing decisions.

Do this monthly, not once. Webflow updates can affect performance. Third-party scripts you embed get heavier over time. A new image in a slider can silently push your LCP into the red. The only way to catch regressions is to check on a schedule.

In Google Search Console, the Core Web Vitals report shows which pages fail across your real users' devices — not just a lab simulation. If you have multiple pages flagged, start with your highest-traffic pages first.

A green CWV score doesn't guarantee top rankings. But a red score is a ceiling on how far you can go, especially on competitive keywords where every signal matters.