Test how fast a page loads on mobile and desktop: Core Web Vitals from real visitors, a lab test, and the fixes that would help most.
Test the pages that matter most — home, pricing, top articles.
Mobile uses a mid-range phone on slow 4G, like Google does.
Suggestions are sorted by how much time they save.
Real-visitor data is what people actually experienced over 28 days on their own devices. The lab test is one load under fixed conditions — useful for finding causes, but not what Google ranks on.
The real-visitor Core Web Vitals (LCP, INP, CLS). A page passes when all three are good for at least 75% of visits.
Google only publishes it for pages and sites with enough Chrome traffic. Use the lab test, or the extension to measure your own visits.