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google-pagespeed

Understand the Google Page Speed Insight Results

I just use Google Page Speed Insight to check my website, and get the following result:

enter image description here

I try to read the help document at https://developers.google.com/speed/docs/insights/v5/about but I still have some questions:

  1. The result said "does not have sufficient real-world speed data", why there is still a "Origin Summary" contains the distribution of the Core Web Vitals in the past 28 days as they are just real word speed data?

  2. I run the check for several times, and find the Origin Summary will be the same for the most of the time. So the distributions come from the past 28 days, not the current analysis result. And the document also confirm this. However, after several more tests, I find the data in Origin Summary will also change a little, for example, the CLS in the summary will changed from 0 to 0.03 to 0.02, that make me confused.

Solution

  • 1. The result said "does not have sufficient real-world speed data", why there is still a "Origin Summary" contains the distribution of the Core Web Vitals in the past 28 days as they are just real word speed data?

    "Does not have sufficient data" only refers to field data for that particular page. For lower-traffic pages it's common that individual pages won't have enough data - but the origin will.

    2. I find the data in Origin Summary will also change a little, for example, the CLS in the summary will changed from 0 to 0.03 to 0.02, that make me confused.

    The number in the origin summary (e.g. 0, 0.03, 0.02) refers to the 75th percentile of that metric over the past 28 days. A CLS of 0 vs. 0.03 is a very small difference so its not surprising to see this level of fluctuation over time.