Blog / Articles14 November 2018

Google PageSpeed Insights updated. How will this affect site ratings?

On November 12, Google released the update for PageSpeed ​​Insights, a tool for evaluating download speeds for sites, without any loud announcements. This is the first large-scale change in this service since January 2018, when it received data from Chrome User Experience Report.

The update fundamentally changes the approach to page analysis: now the speed is estimated basing on Lighthouse data, loading time metrics in seconds are displayed for any site, and many new parameters and recommendations appear in the report. However, first things first.

We can already see that the performance scores of many sites changed significantly, especially for mobile devices. Even the scale itself has changed. "Low", "medium" and "good" optimization scores now occupy other numerical ranges. What should we expect from this update? Should you panic about the fact that your site is now rated worse?

How it was earlier: PageSpeed ​​Insights interface before the update

Before the release of the update, the report of the tool looked like this:

In this article, we have already figured out how to use it and what information you can receive from it, therefore here we only give a brief list of the sections that made up the old interface:

  • loading speed score from 0 to 100;
  • Chrome User Experience Reportdata, available only for sufficiently visited sites, with two speed metrics (First Contentful Paint and DOM Content Loaded) and their statistical distribution;
  • brief information about page loading: the amount of data transferred and the number of accesses to the server;
  • a list of PageSpeed ​​Insights rules (altogether 10 rules existed) that are not realized on this page, with advice for optimization;
  • the list of completed rules (possibilities for acceleration by these rules are almost absent).

How it is now: the updated PageSpeed ​​Insights interface

After the upgrade, the service has the following form:

As you can see, the structure of the report now contains the following sections.

1. Performance score

At first glance, the system remained the same: three colors and three ranges. However, the changes affected the scale. Let’s compare the old and new scores in the table:

Range color

Old score

Old value range

New score

New value range



80 – 100


90 – 100



60 – 79


50 – 89



0 – 59


0 – 49

Thus, even the names of the indicators themselves speak of a changed approach: the emphasis now is not on the level of optimization, as before, but exactly on speed. We'll talk more about this below. Looking ahead, we should say that the new score is not equal to the old one, since it is based on other metrics.

2. Field Data

This is, in fact, the information from Chrome User Experience Report. As before, it can be seen only for those sites that have enough statistical data. FCP (First Contentful Paint) metric remained the same, but First Input Delay (FID) came instead of DOM Content Loaded (DCL). FID indicates the time between the user's first interaction with the site (clicking on the link, button, etc.) and the moment when the site responds to this action. Maybe Google considered that the FID is more relevant when it comes to statistics on how real users work with a web resource.

In addition, at the bottom of this section you can see "Show Origin Summary" button. This is a new and more convenient way to view the average data on the site as a whole, without typing a special command before the site address. You can read here about how this feature worked before.

3. Lab Data

This section contains the speed metrics obtained with Lighthouse by emulating the page load in a 3G network. The main difference from the old interface is that all metrics are shown in seconds, so information about the loading time is now visible for any sites. However, you should remember: this is only an emulation, and these values may differ both upwards and downwards for real users.

There are six metrics in this section:

  • First Contentful Paint. This is the same metric as in the Field Data section, but here it is obtained in "lab" conditions. It shows the time from the beginning of the loading until the moment when at least one element of the page appears on the screen;
  • First Meaningful Paint. Displays the time from the beginning of the loading until the main content of the page appears: above-the-fold-content and web fonts are drawn;
  • Speed ​​Index. Shows how quickly page content becomes visibly populated. It is determined by frame-by-frame comparison as the moment when the page ceases to change visually;
  • First CPU Idle. This is the time when the main thread of the page is free enough to react the user's actions. The most, but not all, of the page elements are already interactive, and the page responds to the user's actions in reasonable time;
  • Time to Interactive. Shows the time for which the page is fully loaded and ready to interact with the user: event handlers are registered for most of the visible elements, the response time is no more than 50 milliseconds;
  • Estimated Input Latency. Shows the average response time of the page during the busiest 5 seconds of the loading. If this value exceeds 50 milliseconds, then users may receive your site as laggy.

These metrics are not new, as they have appeared in Lighthouse a long time ago. Together they allow a comprehensive assessment of page performance. We can see not only how fast the page loads, but also its ability to respond to interactions and the speed of these responses.

It is important to note that the total score on a scale from 0 to 100, which appears in the first section, is calculated basing on these six metrics (to be more precise, only five of them — Estimated Input Latency is not taken into account). These metrics have different weights, which can be seen here: Time to Interactive is the most important; First Meaningful Paint is the least significant. The mechanism of calculation is following:

  • the value of each metric in seconds is compared with this metric for sites from HTTP Archive database;
  • the time value is transformed into a 100-point scale based on the logarithmic distribution (the higher the percentage of sites having this metric worse is, the better will be the score);
  • the five scores are averaged taking into account the weight of each metric, which forms the final page score.

4. Opportunities, Diagnostics and Passed audits

The bottom three sections of the new report correspond to the old recommendations section; however, the previous 10 rules were replaced by 22 Lighthouse performance audits. These indicators are not new too, but they migrated to PageSpeed ​​Insights just now. None of these metrics is taken into account when calculating the final score; they are only the tips about what exactly you can fix on your page to improve its performance. These sections look like this:

Tips displayed in the Opportunities section have the approximate values of load time saving in seconds. For comparison, before, savings were displayed only in kilobytes of traffic, and for viewing them, you had to deploy each tip. This information can also be seen now. Many of the recommendations in this section are related to images, as well as to the elimination of files that block rendering:

  • use the appropriate image size;
  • defer offscreen images;
  • use up-to-date image formats;
  • defer unused CSS;
  • eliminate render-blocking resources, etc.

Other recommendations, more difficult to evaluate in seconds, are in the Diagnostics section. By deploying each of them, you can also get more information: for example, what potential traffic savings can be received by caching certain files or by the use of deferred script loading.

All audits that Lighthouse considered successfully completed for this page (that is, there are practically no opportunities to accelerate by them) come into Successful audits section.

What does this all mean?

First, it means the fact that Google decided to shift the emphasis in PageSpeed ​​Insights. Previously, it was about the abstract "optimization". Although it showed how quickly or slowly your page works, but it did not give a data about ​​the real speed. Now the specific values in seconds are shown. For example, after compressing images you can see that the page began to load 2 seconds faster. Let's hope that this will be an important step towards real acceleration of the Internet instead of a race for abstract metrics, which site owners are often fond of.

Another possible reason for the update is the desire to keep up with the development of other services of the company. For example, Google recently released a lazy loading guide: if you follow the recommendations in it, the search engine should see lazy-loaded content. In PageSpeed ​​Insights, a corresponding audit appeared. It is called "Defer offscreen images" and recommends applying lazy loading.

Also, note that the update expands the concept of "site speed": not only the time when we can see the page and its elements affects the score, but also the readiness of these elements for work, their ability to respond to our actions too. Lighthouse describes it well by the "performance" word.

However, not everything is clear in the work of the updated tool so far. We can note that for many sites the scores on mobile devices have become lower, even considering the changed scale: the resources that used to receive "average" ratings (yellow zone) are now scored as "slow" (red). At the same time, desktop scores changed not so significantly and even improved sometimes.

In the first days after the update, the tool may receive morerequests, because there will be more people willing to see the changes. So if you can’t check your site, just wait for a while.

You should not panic if you see that the speed rating of your site has dropped significantly: most likely, this is caused by changes in the algorithm and is not connected with the site itself. Do not make rash actions, especially if you are not sure of their correctness and do not have the necessary technical knowledge: you risk not to improve the pages performance, but to harm them. It’s better to wait for some time, because it is possible that the mechanisms of PageSpeed ​​Insights will be refined in the near future if any errors are discovered.

If you understood that your website needs to be accelerated, and you cannot do it without the help of specialists, then ARTO web agency is ready to offer you its services. Contact us, we are always glad to help!

Nikolay Ashpin
SEO, blog editor
I have been engaged in copywriting since 2014, in SEO - since 2017. I am interested in Internet marketing modern trends and search engine optimization, as well as in the capabilities of the Google My Business tool, and I share the experience of using it at seminars and conferences. If you have a question about this article, please write to

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16 November 2018, 15:26
Спасибо за статью. Тоже заметил, оценка скорости на мобильных устройствах стала в некоторых случаях намного ниже, чем была ранее. Будем наблюдать ...
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