Brief overview of the Google PageSpeed Insights transformation into Google Lighthouse and Core Web Vitals.
Google PageSpeed Insights
PageSpeed Insights [PSI] was the first Web Performance Optimization [WPO] tool found by Google.
The first five versions of PageSpeed used simulated lab-test metrics measuring basic website performance. The specific measuring algorithm and stable IPs of the PSI crawlers allowed easy manipulation that was implemented into specific WordPress plugins.
In 2018 Google extended the Google PageSpeed Insights and made it one of the five metrics of Google Lighthouse tool.
The Google Lighthouse grew into an automated tool for improving the performance, quality, and correctness of the web, focussed on:
- Performance metrics,
- Accessibility accordance,
- Best Practices compliance,
- Search Engine readiness,
- Progressive Web Apps.
Core Web Vitals
In 2019 Google introduced the per-page Core Web Vitals [CWV] and added it to the Google Search Console.
In the end of 2020 the Core Web Vitals was officially announced as a new ranking factor starting 1st of May 2021.
The three major Core Web Vitals per-page metrics are:
- Largest Contentful Paint (LCP): measures loading performance of page [less than 2.5 seconds].
- First Input Delay (FID): measures interactivity of page [less than 100 milliseconds].
- Cumulative Layout Shift (CLS): measures visual stability of page [less than 10%].
Chrome User Reports
Google started to collect Chrome UX Reports data in 2014 after changing its Chromium based Chrome browsers to its own Blink Engine [away from Apple’s WebKit]. The data formed the Google BigQuery project, which aggregates user experience metrics by origin and various dimensions.
Since 2020 the CrUX is used in Google Search Console, Google Lighthouse tool as the Core Web Vitals real-world metrics that are impossible to manipulate.
Since 2021 the validation of the pages with the Core Web Vitals issues in Google Search Console is now based on 4-week monitoring period of the CrUX data.