Page performance does not appear accurate compared to Pagespeed insights.

[jmumby]

When comparing pagespeed insights results with visits around the world the performance report shows much slower page load times than what is experienced.

Matomo report:

Page insights

Is there a way to troubleshoot why this might be?

[michalkleiner]

This can be influenced by several different factors.

Considering it is indeed comparing the same page and only one page, not a single page vs average across the site, one thing could be that the visitors' browsers/processing is slower and therefore the reported times are higher.

It could also be desktop vs mobile difference, are the same times experienced when measuring desktop? Are the page insights measured locally or over the Internet?

[rr-it]

This is related to #17847

Matomo collects data about classic performance indicators:
network, server transfer, DOM processing, DOM completion, onload event

PageSpeed Insights collects special performance indicators only implemented by the Blink engine implemented in Chrome/Chromium based browsers

Important metrics to measure – see web.dev:

• Time to First Byte (TTFB): web.dev / MDN Web Docs Glossary
• First Contentful Paint (FCP): web.dev / MDN Web Docs Glossary
• Largest Contentful Paint (LCP): web.dev / MDN Web Docs Glossary
• First Input Delay (FID): web.dev / MDN Web Docs Glossary
• Time to Interactive (TTI): web.dev / MDN Web Docs Glossary
• Total Blocking Time (TBT): web.dev
• Cumulative Layout Shift (CLS): web.dev / MDN Web APIs
• Interaction to Next Paint (INP): web.dev

As a new feature Matomo might also collect these special performance indicators - related to #20726

[rr-it]

@jmumby If you are able to 'patch' your matomo instance, have a look at this PR #20718
Any feedback is very welcome on this!