Free PageSpeed & Core Web Vitals Checker
Enter any page URL to measure it with Google Lighthouse — the 0–100 performance score plus Core Web Vitals (LCP, CLS, TBT) on mobile or desktop. Instant, free, no signup. Scheduled monitoring is available separately on paid Team plans and higher.
What are Core Web Vitals?
Core Web Vitals are the three user-experience metrics Google uses as a page-experience ranking signal: Largest Contentful Paint (LCP — how quickly the main content renders), Cumulative Layout Shift (CLS — how much the layout jumps around while loading), and interaction responsiveness (Interaction to Next Paint, or INP; in a lab test its closest proxy is Total Blocking Time, TBT). This tool reports LCP, CLS, and TBT, plus First Contentful Paint and Time to First Byte, with Google's official good / needs-improvement / poor bands.
How is this different from Google PageSpeed Insights?
It uses Google Lighthouse through the PageSpeed Insights API. This free tool gives you one measurement when you run it; results can vary between runs. Paid Team plans and higher can also re-measure opted-in assets on a schedule and alert on qualifying regressions.
What is a good performance score?
The Lighthouse performance score runs 0–100. 90–100 is fast (green), 50–89 needs work (orange), and below 50 is slow (red). The score is a weighted blend of the lab metrics — LCP, TBT, CLS, and a few others — so a single heavy metric can pull it down. Mobile scores are usually lower than desktop because the test throttles CPU and network to model a mid-range phone; that is why this tool lets you switch between mobile and desktop.
Why does the score change between runs?
Lab measurements have run-to-run variance: a CDN cache-miss, a slow third-party script that loads on one run and not another, or normal network jitter can move the score a few points. That is exactly why a single measurement is a weak signal for whether your site is actually getting slower. A trend line — the same page measured repeatedly over days — is what separates real regression from noise, and continuous monitoring is what produces that trend.
How do I keep my pages fast over time?
Re-test after changes to images, scripts, dependencies, or server response times, and compare results over time. Scheduled PageSpeed / Core Web Vitals monitoring requires a paid Team, Agency, or Compliance plan. Free, Starter, and the no-card 14-day trial do not include it. The public PageSpeed checker is free without an account. Moving from Free to Starter does not add scheduled performance monitoring; upgrading to Team or higher lets you enable it for your assets. The no-card trial does not unlock this feature, and an expired trial becomes read-only unless you upgrade.
Related reading
Track performance over time with Team
Scheduled PageSpeed / Core Web Vitals monitoring requires a paid Team, Agency, or Compliance plan. Free, Starter, and the no-card 14-day trial do not include it.
One-off PageSpeed tests remain free, with no signup. For free account monitoring, start with SSL and DNS checks instead.