It has become a bit boring to mention how important the overall user experience is to the success of a website. And one of the most important items when it comes to this is the site loading speed. Users have less and less patience to wait for slow and poorly designed sites. Therefore, it is necessary to monitor all parameters and use the tools that Google offers us for free in order to determine how technically well-designed and well-designed the site is and what its loading speed is.

Different measurement of site speed in Search Console and PageSpeed ​​Insights

However, what happens when two Google tools give us completely opposite data and website speed ratings? Google ‘s John Mueller explains why the Search Console Core Web Vitals report differs from the PageSpeed ​​Insights results. He explains why two page speed measurements never match and why it makes sense that they don’t.

The question John was asked was:

“When I check the PageSpeed ​​Insight score on my website, I see one number. Why doesn’t it match what I see in Search Console in the Core Web Vitals report?

Which of these numbers (results) is correct?”

Muller replied:

“I think maybe the first thing to state, in order to get an obvious answer, is that there is no exact number when it comes to speed, when it comes to understanding how your website is performing for your users.”

In PageSpeed ​​Insights, by default, I believe we show a number that’s a score from 0 to 100, something like that, that’s based on a number of assumptions, where we assume that different things are a little faster or slower for users.

And based on that we calculate the result.

In Search Console, we have Core Web Vitals information based on three numbers for speed, responsiveness, and interactivity.

And these numbers are a little different, of course, because they are three numbers, not just one number. “

Field and laboratory data

He then tried to explain this difference and continued:

” But there’s also a big difference in how those numbers are determined.”

Namely, there is a difference between so-called field data and laboratory data.

Field data is what users actually saw when they went to your website. And this is what we use in Search Console.

That’s what we use for search as well.

Whereas the lab data is kind of a theoretical view of your website, like where our systems have certain assumptions where they think, so the average user is probably like this, using this kind of device and maybe with this kind of connection.

And based on those assumptions, we’ll estimate what those numbers might be for the average user.

And of course you can assume that those estimates will never be 100 percent accurate.”

So what Mueller is saying is that Search Console results reflect what actual site visitors saw.

Two tools, two measurement purposes

The way Google measures those actual numbers is through visitors who have allowed Chrome to provide anonymous basic data about vital web data.

Google does not measure every site visitor, only those who chose to send that data to Google .

In contrast , PageSpeed ​​Insights creates a simulation of what a user might experience.

The purpose of Search Console data is to show what real site visitors are experiencing.

The purpose of PageSpeed ​​Insights data is to provide an assessment of what is happening to provide diagnostic feedback on what may be causing poor website speed performance.

Mueller then comments that even though Search Console is based on actual site visitors, the data will vary and not be consistent.

He explained:

“Similarly, the data that users have seen, and that will change over time, where some users may have a very fast connection or a fast device and everything is going very fast on their website or when they visit your website.”

And others may not have it.

And because of this, this variation can always result in different numbers.

Our recommendation is generally to use data from the field, data that you would see in Search Console, as a way to understand what the current situation is for a website.

And then to use the lab data, which is the individual tests that you can run yourself, to optimize your website and try to improve things.

And when you’re pretty happy with the lab data you’re getting with your new version of the website, then over time you can collect data from the field, which happens automatically, and double-check if users actually see the site as faster or more responsive.

So, in short, again, there is no absolutely correct number when it comes to any of these metrics.

There is no absolutely correct answer where you would say, that is what it should actually be.

But rather, there are different assumptions and different ways of collecting data, and each of them is different in its own way.”

Each tool has its purpose

Perhaps a useful way to think about the two metrics is that they are both useful, but for two different purposes.

Search Console Core Web Vitals data is derived from real visitors and provides what the user experience of site visitors is like in the real world (data from the field). Real site visitor data can highlight problems that might not show up in a simulated sample.

PageSpeed ​​Insights results are simulated results for the purpose of analyzing and troubleshooting page speed. This tool identifies problems that prevent pages from loading quickly and offers suggestions on how to fix them.

The data sources are different so they will never match exactly. But that doesn’t matter, because the intent for each tool is different.

Google ‘s official documentation for the Search Console CWV report says:

“The Core Web Vitals report shows URL performance grouped by status, metric type, and URL group (groups of similar web pages).”

The purpose of the PageSpeed ​​Insights tool is stated on the tool’s webpage:

“Speed ​​up your websites on all devices”

In short, each tool has a purpose:

• The purpose of the Search Console tool is to provide a detailed cross-section of a site’s real-world performance.
• The purpose of PageSpeed ​​Insights is diagnostics, to identify problems and offer suggestions for improvement.

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Source: searchenginejournal