Core Web Vitals Top Websites Scorecard
What are Core Web Vitals?
Core Web Vitals or CWV are a set of metrics that measure user experience. They focus on speed, interactivity, and even visual stability of a website. These ‘vitals’ are imperative to provide a good user experience to those visiting your website. Google will be using three core web vitals signals to determine the page experience which will input into rankings assessments from May 2021.
For more details on what each of the Core Web Vitals are and what they mean for your business, see our guide on How to Prepare for the Google Page Experience Update in 2021 [+ Checklist].
In our research we have found only 8% of the top 100 global websites have a Core Web Vitals score above 75, whereas the majority have a poor score of under 49 with 80% of the top 100 global websites receiving a poor Core Web Vitals score.
So what does this mean?
Currently the majority of the larger websites are not set-up for the Google’s update in May 2021. Whilst brand terms are likely to be unaffected by this change, for generic terms the websites that receive a poor Core Web Vitals score could see their competitors gain on search visibility if their Core Web Vitals score exceeds that of the top 100 websites.
The Core Web Vitals update is an additional signal for Google to evaluate relevant results for search terms, as a result it needs to be treated as part of a bigger SEO strategy. Larger websites, with authority and high relevancy are unlikely to see significant changes unless their competitors with equivalent SEO equity takes advantage of the Core Web Vitals Google update.
We believe, the impact of the Core Web Vitals will be felt more by lower authority pages and highly competitive search terms where the SERPs landscape has a lot of movement between competitors.
Best Performers Worst Performers Data Data Data
How we selected the Top 100 Websites
For the purpose of this research our team selected the top 100 global websites using Amazon’s Alexa Top Sites. The top websites are calculated using the combination of average daily visitors and pageviews over the last month. This ongoing dataset calculation provide the latest list of top global websites.
How do we assess the Top Website’s Page Experience?
Using Alexa’s top website list, we evaluate the homepage URL for each domain using Google’s page speed insight tool as this provides metrics against all three Core Web Vitals factors.
To collect the data, we ran the tool for all websites’ homepage URLs 3 times for each site over the same day to account for fluctuations. Our data is an average score of these results.
How is the score calculated?
Using Google’s metric calculations documented in their Lighthouse tool, we were able to apply the calculations like-for-like and applying the weighting for the three factors as per Google’s Calculations. Google states “All tests are run using a simulated mobile device, throttled to a fast 3G network & 4x CPU slowdown”.
In our calculations, we have applied the weighting based on the latest versions (V6 & V7) based on mobile traffic.
Using Google’s performance scoring calculations, our scorecard uses the Lighthouse scoring distribution which is “a log-normal distribution derived from the performance metrics of real website performance data on HTTP Archive”.
For Time to Interaction (TTI) which is includes First Input Delay Google’s Lighthouse scoring curve model uses HTTPArchive data which establish two control points that then sets a log-normal curve shape.
Once we have extracted Google’s performance scoring for Core Web Vitals metrics, over 3 tests within the same day, we use the average and apply the weighting percentages as stipulated by Lighthouse’s calculations (LCP 25%, FID (using TTI percentages) 15% and CLS 5%. As we are only looking at factors that make up 45% of the overall performance score, we have adjusted the formula to make this 100% of the score value, which provides a total score out of 100.
To understand what a good score and a poor score is we have interpreted this as:
Good: 100 to 75
Needs Improvement: 74 to 50
Poor: 49 to 0
Core Web Vitals Data Visualisation Assets
We invite you to use our data and our downloadable assets around our Core Web Vitals research. We do ask that you reference and link to us in return.