What does a website speed test measure?

A website speed test measures loading and interaction behavior and reports Core Web Vitals such as Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift alongside lab diagnostics. Those metrics help prioritize work affecting real user experience and search performance.

This tool queries Google PageSpeed Insights, which runs Lighthouse on Google infrastructure and may also expose available field data. Lab results are a controlled snapshot, while field data summarizes eligible Chrome visits over time. Location is not selectable, and one run should not be treated as a production performance trend.