How Google’s Core Web Vitals will Rank Websites

Let’s get to the bottom of how Core Web Vitals (CWV) will work. Here’s five answers to questions we keep hearing.

Core Web Vitals is Google’s next big algorithm update, which becomes a ranking signal in May 2021. Three primary metrics, including Largest Contentful Paint, First Input Delay, and Cumulative Layout Shift, are designed to measure how users experience the speed, responsiveness, and visual stability of webpages.

While there’s a lot of general information about Core Web Vitals, foundational questions about where and how data will be scored are a bit more mysterious. As we manage millions of pages — all focused on passing Core Web Vitals — we’re in a unique position to predict how the ranking signal will work. Enjoy.

1. What data does Google measure to score Core Web Vitals?

While lab data from Lighthouse offers a performance barometer, the source of truth is CrUX data. According to Google’s Web.dev, “the Chrome User Experience Report collects anonymized, real user measurement data for each Core Web Vital.” It all comes down to field data — what user’s perceive and see in practical applications.

2. Are CrUX scores impacted by the AMP Cache?

The AMP framework has a unique advantage as pages are pre-fetched and served from the cache. The combination creates a seemingly instant page load. John Mueller has offered insights, saying that Google will use the page experience scores based on what the searcher will see after they click over from Google to the web page. And if you have AMP, Google serves the AMP version to users on mobile. Thus the AMP page is what Google will use for measuring with core web vitals.

The conclusion is that CrUX field data — and what users experience — is what Google will benchmark against Core Web Vitals. And for those of you using AMP, experiences served from Google’s AMP cache are attributed to the publisher’s origin in CrUX. This May, when the update takes effect, AMP-enabled websites should reap the rewards.

3. Is CWV a sliding scale or pass/fail?

A safe bet is Core Web Vitals will be pass or fail. Here’s the rationale:

  • Google Search Console has three states — poor, needs improvement, and good — an indication that pages either pass (good) or fail (poor or needs improvement).
  • PageSpeed Insights also indicates, simply, that pages either pass or does not pass.
  • Lastly, Google is experimenting with a fast-label badge to indicate performant pages in search. To do this, pages must be either pass or fail.

4. Does CWV only impact search results on mobile?

Yes. Google has clearly stated that using Page Experience as a ranking signal only applies to mobile search. This also follows Google’s growing focus on small screens, as the search giant has rolled out mobile-first indexing and hinted at a future where it’s purley mobile only.

5. Will Google score Core Web Vitals at the URL or the origin level?

Google says “Core Web Vitals thresholds are assessed at the per-page level, and you might find that some pages are above and others below these thresholds.”

We can improve page experience on your mobile site or web app

To learn more about our speed-optimization platform, schedule a discovery call here. WompMobile XDN bolts-on to any website to immediately deliver sub-second page loads. Let’s explore how we can help tick off all the Core Web Vitals boxes.