We'll talk about what's important to get your website included in the Chrome User Experience dataset and what aspects Core Web Vitals (CWV) are measuring to evaluate the user experience of your visitors.
What Makes PageSpeed Insights (PSI) Display Real-World Data
There is a very specific criteria to which pages need to adhere for PSI to display real-world data when auditing them. Essentially, Google needs to be able to create a Chrome User Experience (CrUX) report for a page in question.
CrUX report is based on data from Google’s real user monitoring tool, which can only monitor Chrome users that:
- Are logged in with their Google Chrome profile
- Have active browser history synchronization without passphrase
- Enabled usage statistic reporting
For a page to be eligible for becoming a CrUX data source, it needs to be publicly discoverable and sufficiently popular.
To clarify further, the page is considered publicly discoverable when it doesn’t:
- Return HTTP status code other than 200
- Return HTTP X-Robots-Tag: noindex header or equivalent
- Include <meta name=”robots” content=”noindex”> meta tag or equivalent
And for a page to be sufficiently popular, it needs to have a certain minimum number of visitors in the last auditing period. Furthermore, an origin (base URL) is determined to be sufficiently popular when it has this undisclosed minimum number of visitors across all of its pages.
So if we consider the scenario we mentioned at the beginning of this post, this might be the cause why you get real-world data for origin and not for individual pages.
Understanding Core Web Vitals for Real-World Data in PSI
PageSpeed Insights uses a handful of metrics that define the quality of performance of your website. Furthermore, there are three that stand out the most, which we also call Core Web Vitals (CWV).
Largest Contentful Paint (LCP)
This metric measures the time it takes for the largest element to load into the viewport. Moreover, before this element loads, visitors won’t be able to see almost anything on your site.
And it’s usually the most relevant for user experience since it has the biggest impact on load speed.
However, it doesn’t have the same weight when it comes to the overall SEO score of the page. LCP accounts for 25% of the score, which is still a big chunk of it, but there is also one metric that’s even more impactful.
First Input Delay (FID)
FID measures the time it takes for the browser to respond to the user’s first interaction with the page. These include clicking on a link, or button and/or interacting with any other element on the page.
Whenever we come across a page that performs poorly on this metric, we might experience unresponsive elements if the page hasn’t loaded yet completely. Therefore, it’s even more important than the LCP metric, accounting for 30% of the overall SEO score.
Cumulative Layout Shift (CLS)
Last, but not least, the CLS metric measures the visual stability of your page. To explain, it detects elements that cause the page layout to shift or move while loading.
This phenomenon can be quite frustrating whenever we try to click on a button or link, just for them to move out of position. Even more so if we end up clicking on an ad that sends us to another site entirely.
Conclusion
To conclude, we established that PageSpeed Insights can only show real-world data for pages that are publicly discoverable and sufficiently popular among users that adhere to specific criteria whose individual user experiences can be collected into CrUX dataset.
