The real data in Pagespeed insights

Text/software engineer Mushan Yang and Xiangyu Luo

Pagespeed Insights can provide the effect of a Web page compared to a set of best practices. In the past, these recommendations were not referenced by the actual speed of the Web page, which made it difficult to understand whether the optimizations were appropriate to apply. Today, Pagespeed Insights will use the data from the Chrome User Experience report to provide better advice to developers, and the tuning score has been adjusted to better match real data.

The PSI report now has several different elements:

The speed score classifies the page as fast, medium, or slow. The score depends on the median of two metrics: first content drawing (FCP) and DOM content loading (DCL). If two indicators are in the top One-third in their respective categories, the page will be categorized as "fast."

The optimize score divides the pages into "good", "medium", or "low" by evaluating the performance optimization space. The calculation assumes that the developer wants to maintain the same page appearance and functionality.

The Page load Map section displays the distribution of the FCP and DCL events in the data set for the corresponding page. After comparing all the events in the Chrome User Experience report, these events are divided into: fast (top One-third), Medium (middle One-third), and slow (after One-third).

The page Statistics section shows the number of round trips that are required to load the blocked rendered resources used by the Web page, the total number of bytes used by the corresponding pages, and how they compare to the number of round-trip times in the dataset and the median number of bytes used. This section can indicate if the developer modifies the appearance and functionality of the corresponding Web page, the loading speed is likely to be faster.

Optimization recommendations lists best practices that you can apply to the appropriate pages. If the corresponding pages are loaded faster, these suggestions are hidden by default because in all pages in the dataset, the corresponding pages are already in the top one-third.

For more detailed information on these changes, see Pagespeed Insights Introduction:

Https://developers.google.cn/speed/docs/insights/about

As always, if you have any questions or feedback, please visit our forum (Https://groups.google.com/forum/#!forum/pagespeed-insights-discuss) and remember to add the URLs to be evaluated.