Update : The Google SEO checker can now also analyze how your URL performs based on Google PageSpeed metrics.
The Google SEO Checker is powered by the official Google Lighthouse platform, designed to improve the quality of a web page. Enter your URL and get access to how Google sees your website. Based on 14 key metrics Google will give you basic feedback and insights on how well your website is optimized for search.
Because Search is Google’s top product, Google has been helping webmasters, website owners and developers with different types of resources to improve performance and indexability of their sites. These resources include the Google Webmaster Blog, Search console, the Google SEO Starter Guide, Google Webmasters on YouTube and multiple other tools. The latest tool from Google that’s designed to evaluate your on-page technical SEO efforts is the Lighthouse platform.
The results from the Google SEO audit will help you to understand the on-page basics. To fully analyse how well a website is optimized for search, I recommend you to also have a look at these tools:
The automated SEO analysis is performed by the Google lighthouse platform and reviews your website based on 14 on-page SEO elements. It has to be said that the report is pretty basic, but it does include some helpful checks.
The Google performance report utilizes the Google page speed API to collect both user (field) and lab data for your URL. The results are analyzed and marked, so you can easily identify issues that need your attention. Key metrics that are included in the performance report are: First Contentful Paint, Largest Contentful Paint, Cumulative Layout Shift, Speed Index, Time to Interactive, and Total Blocking Time.
Based on Google’s SEO starters guide, here are some examples and guidelines to help you create a Google-friendly website.
Further reading: https://support.google.com/webmasters/answer/40349?hl=en