Home » Blog » Why my page “does not pass” the Core Web Vitals assessment?

Why my page “does not pass” the Core Web Vitals assessment?

Posted by Surgeon’s Advisor

A man exhausted by poor web performance while working on a computer

Core Web Vitals

Many webmasters have been struggling with the fact that their page still shows as a failing URL in the Core Web Vitals dashboard despite the many efforts and fixes.

What is happening?

We believe this is because of the number of pages with insufficient traffic for Google to collect the data. So it is not too difficult to understand, but for that, we will need to explain what you see in the Page Experience dashboard and how that correlates to the PageSpeed Insight test.

Let’s start with the relatively new Page Experience dashboard.

The Page Experience dashboard

Screenshot of a dashboard showing page experience metrics
“Page Experience” dashboard

Google recently changed the Page Speed dashboard to the new “Page Experience” dashboard. This is a new way to look at different metrics that affect a web page from a user experience perspective. Specifically, the Core Web Vitals metrics: First Contentful Paint (FCP), First Input Delay (FID), Largest Contentful Paint (LCP), and Cumulative Layout Shift (CLS) to measure visual stability, are the ones giving us the headache.

Core Web Vitals’ Good URLs

The percentage of “Good URLs” showing in the dashboard (The Core Web Vitals scores) are the pages passing all of these 4 metrics and is directly related to the number of “Impressions”. The weight of these metrics in the new Page Experience Algorithm update will always remain a mystery but is clear that right now is very high, considering the changes in ranking positions we have seen through June and July.

The PageSpeed Insight test

When testing a page using the PageSpeed Insight test, the resulting score on the big green bubble seems to tell us that everything is great. We are winning! Wait. Apparently, Google is degrading the importance of the speed score by the score of the 4 metrics mentioned above (the Cumulative Layout Shift and the others). Keep reading the test result and the first paragraph below the score says:

Field Data – The Chrome User Experience Report does not have sufficient real-world speed data for this page.

From PageSpeed Insight test

What is that supposed to mean? I think the reason why this is the first paragraph right after the “score” number is that it directly impacts the results of “Good URLs” that Google Search Console is showing in the Page Experience dashboard.

Screenshot of a PageSpeed Insight test results
PageSpeed Insight test

Understanding Core Web Vitals test results

Core Web Vitals test results depend on the collection of 28 days of Field data. If you are paying attention to the PageSpeed Insight test, you may have noticed that you have Field data and Lab data:

  • Field data: Represent real-world historical data collected by Google through users using the Chrome browser. These are the results that count in the “Good URLs” percentage.
  • Lab data: This is a simulation that happens when you submit the page to the test.

As Google well explains in the FAQ section of the Page Speed Insight test, the two results may contradict each other. One is real historical data and the other is just a one-time simulation.

But wait, what happens if I fix my page but my page does not have enough traffic for Google to collect 28 days of data?

So why my URL still “do not pass” the test?

We did another test for URLs not passing the test. We went to the Core Web Vitals dashboard and clicked on the URL fails.

Screenshot of URLs failing Core Web Vitals test because of CLS
Core Web Vitals details. Validation failed.

From there, we copied the URLs and checked the Clicks data of 3 months for each URL on the Performance Dashboard of the Search Console. What we find out is that many of the URLs do not have enough clicks, therefore they will still show up as “failing” URLs even when we have fixed the issue. In the example below the page in question has only 14 clicks in 3 months. If the 14 clicks are divided between Chrome and other browsers, then when will Google have 28 days of historic data? In about 6 months. In another year? it depends on many factors.

Screenshot of clicks data of 3 months for each URL on Search Console Performance Dashboard
Performance Dashboard in Search Console

How important is the lab data?

We know we fixed the issue because the Lab data shows all the metrics in green. Still, these pages “do not pass” the assessment because the Field Datadoes not have sufficient real-world speed data.” So do not be discouraged by the results Search Console is showing. The Lab data simulation is proof that you did it right. So what is the next step?

If the Lab data is telling you everything is alright, but the Core Web Vitals report keeps showing failing URLs, then there is one more thing you should do: Delete the pages that do not have enough traffic.

Wait, what? Let’s say that you have 100 pages on your website. You fixed all of the Core Web Vitals issues on each page. But of the 100 pages, only 20 have “sufficient real-world data.” In the eyes of Google, only 20% of your website has good URLs.

Screenshot of good results in PageSpeed Insights test
Lab data results in PageSpeed Insights test

Does Google want you to get rid of irrelevant pages?

Apparently, yes. Think about this: if these pages low in traffic are affecting your site’s search performance, and do not have traffic, what is the purpose of having them on your website? To find out, Do a Page Experience score content audit. You can use SemRush or AHREFS tools to perform the audit. Select a year of traffic data and create a report of clicks and backlinks. Set your own limit of what you consider important, but a page with less than 50 visits and no backlinks in a year, has no practical use for your site.

We have tested this strategy and guess what? Websites started to show more “Good URLs!”


What are “Good URLs”?

Good URLs are the percentage of mobile URLs with both Good status in Core Web Vitals and no mobile usability issues according to the Mobile Usability report in Search Console.

What is Field data?

This is the real-world historical data collected by Google through users using the Chrome browser. These are the results that count in the “Good URLs” percentage.

What is Lab data?

Is a simulation that happens when you submit the page to the test. These DO NOT count in the “Good URLs” percentage.

What are irrelevant pages?

Pages that have no meaningful amount of traffic and no backlinks in a year timeframe, though the amount of traffic, backlinks, and the timeframe can change according to the website.

What can I do to help improve the loading times of my website?

There are many things one can do to improve the loading speed of a page and other metrics, for instance, removing excessive CSS files and unnecessary third-party scripts, reducing the file size of images and giving them proper size attributes, implementing lazy load and making sure that Google Lighthouse shows every score in the green (for both the desktop version and the mobile version). If you’re a business owner or just don’t have the technical skills, you can ask your webmaster to reduce the size of the site’s largest elements and make sure the layout is optimized for mobile devices and for real users, not just Google.

An expert programmer working on improving Core Web Vitals

Afraid of a radical solution? We can help.

Contact us. We are a company with 20 years of experience in the SEO industry. We can give you a free evaluation of your website. Not the typical automated report of what is wrong with your site and the magical one-click solution, but a real one of where your website stands right now and what we can do to fix it.