Web Vitals

Add the Web Vitals extension to report LCP, CLS, INP, FCP, and TTFB from visitor sessions.

Enable Web VitalsCopy Anchor Link

Import the extension from its package subpath. It takes no options.

Copy Text
import { webVitals } from "@faststats/react/web-vitals";

<Analytics siteKey="your_site_key" extensions={[webVitals()]} />;

Collected MetricsCopy Anchor Link

The tracker reports the following metrics.

Each metric is sent with its value, an id, a rating, the navigation type, and the delta since the last successfully sent value. Metrics are flushed when the page is hidden and when the client stops, and are attributed to the URL the document was loaded on.

AttributionCopy Anchor Link

Attribution data is always included. Every metric carries the web-vitals attribution fields that point to the element, resource, or interaction responsible for it, such as the LCP element or the INP interaction target. There is nothing to turn on.