Analytics

Next.js Speed Insights allows you to analyze and measure the performance of pages using different metrics.

You can start collecting your Real Experience Score with zero-configuration on Vercel deployments.

The rest of this documentation describes the built-in relayer Next.js Speed Insights uses.

Web Vitals

Web Vitals are a set of useful metrics that aim to capture the user experience of a web page. The following web vitals are all included:

• Time to First Byte (TTFB)
• First Contentful Paint (FCP)
• Largest Contentful Paint (LCP)
• First Input Delay (FID)
• Cumulative Layout Shift (CLS)
• Interaction to Next Paint (INP) (experimental)