LightScout - Core Web Vitals Monitor

Track all 6 Core Web Vitals as you browse. Color-coded ratings, session grouping, CSV/JSON export, and Google Sheets sync.

LightScout monitors all 6 Core Web Vitals in real time as you browse. See exactly how every page performs with color-coded ratings based on Google's thresholds. **Metrics tracked:** - LCP (Largest Contentful Paint) — loading performance - FCP (First Contentful Paint) — initial render speed - TTFB (Time to First Byte) — server response time - CLS (Cumulative Layout Shift) — visual stability - INP (Interaction to Next Paint) — responsiveness - FID (First Input Delay) — interactivity **Key features:** - Color-coded ratings: green (Good), yellow (Needs Work), red (Poor) - Session grouping by domain for easy comparison across pages - Export metrics as JSON or CSV for spreadsheets and reports - Optional Google Sheets sync for historical trend tracking - Tracking toggle to control when metrics are captured - Badge indicator shows page health at a glance **Privacy-first:** All data stays in your browser. Nothing is sent to external servers. No account required — works immediately after install. **Built for developers, designers, and SEO professionals** who want to understand real-world page performance without leaving the browser. Free. No premium tiers. No hidden features. Learn more at https://testscout.dev/lightscout Privacy policy: https://testscout.dev/lightscout/privacy