Google PageSpeed is a family of tools by Google, designed to help webmasters improve their website's performance. PageSpeed Insights is an online tool which helps in identifying performance best practices on any given website, provides suggestions on a webpage’s optimizations, and suggests overall ideas of how to make a website faster.
Mobile / Desktop Score
Per URL request, it grades webpage performance on a scale from 1 to 100
Lab data is performance data collected within a controlled environment with predefined device and network settings. This offers reproducible results and debugging capabilities to help identify, isolate, and fix performance issues.
Opportunities provide suggestions how to improve the page’s performance metrics. Each suggestion in this section estimates how much faster the page will load if the improvement is implemented.
Diagnostics provide additional information about how a page adheres to best practices for web development.