Performance
Performance measures how fast a page loads for real users, based on Google PageSpeed Insights / Lighthouse scores. It contributes 2.5% to the overall score.
Details
Google PageSpeed Insights
The performance data is sourced from the Google PageSpeed Insights API, which runs Lighthouse against the URL. The API returns a Performance score from 0–100 based on Core Web Vitals and other speed metrics.
Core Web Vitals
Google uses three Core Web Vitals as ranking signals:
• LCP (Largest Contentful Paint) — how fast the main content loads. Target: < 2.5s
• CLS (Cumulative Layout Shift) — how much the layout shifts during load. Target: < 0.1
• FID/INP (First Input Delay / Interaction to Next Paint) — responsiveness to user input. Target: < 200ms
Why performance weight is low
Performance contributes only 2.5% to the overall audit score. This reflects Google's own guidance: page speed is a ranking factor but it operates as a tiebreaker. Strong content, technical fundamentals, and authority matter more.
Metrics
| Metric | Description |
|---|---|
| PageSpeed score | Lighthouse performance score from Google PageSpeed Insights (0–100). |
| FCP | First Contentful Paint — time until the first text or image appears. |
| LCP | Largest Contentful Paint — time for the main content element to appear. Target: < 2.5s. |
| TBT | Total Blocking Time — total time the main thread is blocked by long tasks. Proxy for INP. |
| CLS | Cumulative Layout Shift — visual stability of the page. Target: < 0.1. |
| Speed Index | How quickly the contents of the page are visually populated. |
| TTI | Time to Interactive — when the page becomes fully interactive. |