FAQ on passing Core Web Vitals

Do I need a high PageSpeed score?

The short answer is: no you don't. Well, at least not necessarily to pass the Core Web Vitals. This is because the Core Web Vitals will get their data from real user experiences. As a result, the circumstances of your visitors play an important role as well, while the overall PageSpeed score might give you a general impression of your performance and UX hygiene.

Which metrics are important to pass the Core Web Vitals?

Although PageSpeed Insights might show you four metrics, these three metrics are part of the Core Web Vitals:

  • Largest Contentful Paint (LCP);
  • Cumulative Layout Shift (CLS);
  • First Input Delay (FID).

However, as of June 10th, 2021 a webpage (or origin summary) it doesn't matter if your site doesn't have sufficient FID data yet. Passing LCP and CLS metrics will then be enough to pass the Core Web Vitals assessment.

If FID is missing, the page/origin is assessed by its LCP and CLS alone. LCP and CLS are required to be present for CWV to be assessed.

Rick Viscomi

The above means First Contentful Paint isn't part of the Core Web Vitals. Do note that an optimal First Contentful Paint will trigger early user engagement, so don't forget to optimize this metric as well.

Why don't we see changes in the Field data after optimizing our site?

Considering you do see data and charts in the Field data section when using PageSpeed Insights, it is just showing you a summary of the last 28 days. This means, optimizing today isn't enough to skew or impact the data of the other 27 days which might still take the bad experiences into account.

To get an optimal sense of the impact of your changes on the real user experience amongst your visitors, check again in 28 days since optimizing speed / UX.

How fast will Google process our performance updates?

The Field data and thus Core Web Vitals data of real user experience as shown within PageSpeed Insights, is covering data of the last 28 days. As technical optimizations might only become noticeable after 28 new days, chances are it will take at around 28 days.

When Core Web Vitals metrics are already close to the thresholds as set by Google, you might see your webpages or website passing the Core Web Vitals even earlier. Although at time of writing it isn't clear yet how long it takes for Google to impact the SERP's, chances are it will be quite instant, as soon as your webpages or website is passing the Core Web Vitals assessment.

We passed Core Web Vitals, can we now sit back and rest?

It totally depends on your target audience and ambitions. Fast webpages with optimal UX on top of it will allow more users to find and digest your content, causing an increasement in visitors. As this could also allow more visitors under difficult device and network conditions, this could change your averages as well as percentiles.

Besides change in type of users, chances are your website or webshop will grow as well, serving more resources with new risks of impacting the Core Web Vitals metrics. In other words, keep monitoring.

Why don't we see ranking changes?

Ranking also depends on the quality of your content, how your competitors are doing, et cetera. At the end, Core Web Vitals is just one of the many ranking factors of which Google won't tell us how it is used in their algorithms. Maybe your competitors are also doing a great job when it comes to pagespeed and UX, or they have better content quality.