Why Lighthouse Is Not Enough

Lighthouse is an excellent diagnostic tool, but it only measures lab data, not real user experience. Standard practice in 2026 combines lab measurements with Real User Monitoring (RUM).

1. Web Vitals — Chrome UX Report and CrUX API

Google’s Chrome UX Report aggregates field data from real Chrome users. You can query it via API to analyze both your own and competitors’ sites.

const response = await fetch(
  'https://chromeuxreport.googleapis.com/v1/records:queryRecord?key=YOUR_KEY',
  {
    method: 'POST',
    body: JSON.stringify({
      origin: 'https://example.com',
      metrics: ['largest_contentful_paint', 'cumulative_layout_shift']
    })
  }
);

2. Sentry Performance

Well-known for error monitoring, Sentry also offers robust performance tracing. It captures transactions end-to-end, from frontend to backend, with automatic instrumentation for React and Next.js. Setup takes minutes.

3. Datadog RUM

Datadog’s Real User Monitoring combines session replays with performance data. You can inspect individual sessions to see the exact LCP, FID, and CLS each user experienced, then drill into the specific resources causing slowdowns.

4. SpeedVitals

SpeedVitals runs Lighthouse-based diagnostics from multiple global locations simultaneously. It also offers continuous Web Vitals monitoring. The free tier includes enough daily tests for small to medium sites.

5. Grafana + Prometheus + OpenTelemetry

For teams wanting a self-hosted pipeline, collecting browser traces via OpenTelemetry into Prometheus for storage and Grafana for visualization is the de facto standard. It requires more setup but offers complete data ownership.

Use Lighthouse for local development checks, but rely on RUM tools for production monitoring.