Difference between Search Console CWV report and PageSpeed ​​Insights


In a business hours SEO video, Google’s John Mueller explains why the PageSpeed ​​Insights score and the Search Console Core Web Vitals scores are consistently different.

It explains why two page speed metrics never match and why it makes sense that they don’t match.

PageSpeed ​​Insights vs Search Console CWV Report

It’s reasonable to wonder why two things that claim to measure the same thing give different results.

This is the question:

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

Which of these numbers is correct? »

Different page speed scores

John Mueller first mentions that the scores provided by PageSpeed ​​Insights and Search Console are actually different sets of numbers.

He said:

“I think maybe first of all, to get the obvious answer at the door, where isn’t there a correct speed figure, when it comes to understanding how your site Web works for your users.

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

And based on that, we calculate a score.

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

And these numbers are slightly different, of course, because they are three numbers and not just one.

The calculation method is different

Mueller then explains how the scores for the two metrics (PageSpeed ​​Insights and Search Console’s CWV report) are derived and why this yields different scores.

Muller continued:

“But there is also a big difference in how those numbers are determined.

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

Terrain data is what users actually saw when they visited your website. And that’s what we use in Search Console.

This is also what we use for research.

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

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

And of course, you can imagine that these estimates will never be one hundred percent correct.

So what Mueller is saying then is that Search Console scores reflect what actual site visitors have seen.

The way Google measures these actual numbers is by visitors who have agreed to allow Chrome to provide basic anonymized web vitals.

Google does not measure every visitor to the site, only those who have agreed to send this data to Google.

Unlike Search Console field data, PageSpeed ​​Insights creates a simulation of what a user might feel.

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 estimate of what is happening in order to provide diagnostic feedback on what may be causing poor web page speed performance.

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

He explained:

“And likewise, the data that users have seen, which will also 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 site website.

And others might not have it.

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

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

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

And when you’re happy enough with the lab data you’re getting with your new version of your website, you can over time collect the field data, which happens automatically, and double-check that users actually see it as more faster or more reactive too.

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 it should be.

But rather, there are different assumptions and different ways of collecting data and each of them is subtly different.

Two metrics for two objectives

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

Search Console Core Web Vitals data is derived from real visitors and provides a sample of the user experience of site visitors in the real world (field data0). Actual site visitor data may highlight issues that may not be apparent in a simulated sample.

PageSpeed ​​Insights scores are simulated scores intended to analyze and debug page speed issues. This tool identifies issues that interfere with fast page downloads 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 of each tool is different.

google official documentation for the Search Console CWV report States:

“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 indicated on the tool’s web page:

“Make your web pages fast on all devices”

In a nutshell, here’s what each tool does:

  • The goal of the Search Console tool is to provide granular snapshots of actual site performance.
  • The purpose of PageSpeed ​​Insights is diagnosis, to identify problems and offer suggestions for improvement.


Watch John Mueller answer the question in the 31st second.


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