The Page speed tab on the Overview has two kinds of measurement. One comes from your real visitors. The other is Google’s lab test, one load of the page on Google’s own servers; once a result is on screen it’s labelled “Lab: one test by Google”.
Speed your visitors got
“Page speed from real visits” shows three Core Web Vitals, measured in your visitors’ browsers as they load your pages:
| Card | Metric | Good | Poor |
|---|---|---|---|
| Load time | Largest Contentful Paint | 2.5 s or less | over 4 s |
| Response to clicks | Interaction to Next Paint | 200 ms or less | over 500 ms |
| Layout shift | Cumulative Layout Shift | 0.1 or less | over 0.25 |
Each one is graded Good, Needs work or Poor at the 75th percentile: three in four visits did at least this well. Google grades pages on that line rather than the average, so the slowest quarter of visits counts against you.
The numbers appear as people visit, and the card says how many visits were measured. With only a few, expect them to move.
The speed numbers cover the whole site. Vireo Pro adds a list of the slowest pages on the same tab.
Google’s lab test
The same tab has “Test your homepage with Google”, and each post’s stats screen has “Test this post with Google”. Both use Google’s PageSpeed Insights. Choose Mobile or Desktop first.
- Without an API key, the button (“Test this page on PageSpeed Insights”) opens the test on Google’s website in a new tab.
- With your own free Google API key, “Run test” runs it from the dashboard. It takes up to a minute and shows the “Performance score”, the lab timings, and “What Google suggests fixing first”: the five fixes Google expects to save the most.
Results are kept for a day; “Run again” runs a fresh test. A test only runs when someone presses the button.
Add a Google API key
- Create a Google Cloud project, or pick one you already have. Any name works.
- Enable the PageSpeed Insights API for that project.
- On the Credentials page, choose Create credentials, then API key.
- Open the new key. Under API restrictions, choose Restrict key, select PageSpeed Insights API, and save.
- In WordPress, go to Vireo Analytics, Settings, Search Console & API. Paste the key into “Google API key (optional)” under PageSpeed Insights and click “Save API key”.
The settings screen links each step to the right page in Google Cloud. “Remove API key” switches back to opening tests on Google’s website.
Only an administrator can add the key. Other users with dashboard access see a note that an administrator can.
Headless and connected sites
Core Web Vitals aren’t collected from a headless front end yet. A connected site can send them with the optional second tag Vireo gives you.