How To Use the Updated PageSpeed Insight Tool to Boost Performance

For three years, Version 2 of the PageSpeed Insights tool has given website owners information about how effectively their website uses best practice techniques to offer fast loading times.

This information was previously offered without context, though. But Google has resolved this in Version 4, and the tool now uses key metrics and real-world data collected by the Chrome User Experience Report to make better and more accurate recommendations to users.

Here are the key ways that the tool has changed, and how you can make the most of the update to take the speed of your website to new heights.


New Metrics
To offer you more accurate insight into how your website performs, the tool measures two critical metrics using real-world data. The results from these two metrics are spread across three categories: Fast, Average, and Slow:
Let’s take a closer look at what these two metrics mean.

First Contentful Paint (FCP)
FCP is an elaboration on “first paint”, a metric which measures when any render appears within the browser (even a change in background color, for example, would count). The FCP metric measures the time until actual content has been loaded on the page, giving you a more useful user experience assessment.

DOMContentLoaded (DCL)
The Document Object Model (DOM) is an application programming interface that parses HTML, XHTML, and XML documents into a tree structure. The DOM is considered to have loaded properly when there are no stylesheets blocking the execution of JavaScript. This is a critical moment in the loading of a page, and should be achieved as quickly as possible to allow JavaScript to load.

Report Feedback
After analyzing these two metrics, feedback from the tool is delivered across five categories:

  • Speed
  • The Speed score categorizes a page as being Fast, Average, or Slow. This is determined by looking at the median value of the two metrics above: FCP CDL. If both metrics are in the top one-third of their category, the page is considered fast.

  • Optimization
  • The Optimization score categorizes a page as being Good, Medium, or Low by estimating its “performance headroom” – the potential for further optimization that a website has. The calculation assumes that a developer wants to keep the same appearance and functionality of the page.

  • Page Load Distributions
  • The Page Load Distributions section presents how a page’s FCP and DCL events are distributed in the data set. These events are categorized as Fast (top third), Average (middle third), and Slow (bottom third) by comparing to all events in the Chrome User Experience Report.

  • Page Stats
  • The Page Stats section describes the round trips required to load the page’s render-blocking resources, the total bytes used by the page, and how it compares to the median number of round trips and bytes used in the data set. It can indicate if the page might be faster if the developer modifies the appearance and functionality of the page.

  • Optimization Suggestions
  • The Optimization Suggestions section offers a list of best practices that could be applied to a page. It is important to remember that if a page is already fast, these suggestions are hidden by default, as the page is already in the top third of all pages in the data set.

    How to react to this feedback
    After running the test you will have a deeper insight into the performance of your website, and you will also have a series of specific suggestions and recommendations directly from Google. It is possible for you to expand each of these suggestions to explore them in more detail. Each of these expanded views includes a link out to a walkthrough for that particular suggestion, helping your development team to know where to focus. It is worth noting, however, that there may be instances where optimization suggestions appear due to circumstances outside of your control, such as non-optimal caching policies from third-party advertisers.


    How Marfeel uses Google’s suite of testing tools
    Google’s four testing tools (PageSpeed Insight, Lighthouse Test, TestMySite, and Speed Test) are all linked, and each provide a different insight and series of technical information.

    For the PageSpeed Insights tool, Marfeel runs automatic tests each day. The results of these tests are plotted within a database in a time series, and alarms are implemented which are triggered in response to emerging trends or changes. These alarms then alert Marfeel engineers who explore the trend or change, and look into any regressions that might have taken place.

    In terms of optimization, Marfeel ensures that its publishers have 100% of the optimizations implemented so that publisher partners receive the full SEO benefit from being compliant with best practice.

    PageSpeed Insights as a ranking signal
    In its January 17 Webmaster blog post, Google announced that from July 2018 onwards it will use speed as a ranking factor for mobile searches. Known as the “Speed Update”, this algorithmic change will affect pages that deliver the slowest experience to users, so it is going to become increasingly critical for publishers to use tools like PageSpeed Insight to offer the best experience possible.

    If you would like to deep dive into the tech side of the PageSpeed Insights tool, be sure to check out the Marfeel PageSpeed Scores article in Atenea, our knowledge base.

    Interested in keeping ahead of the game when it comes to optimization? Be sure to subscribe to updates from the blog by using the form below:

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