LightScout - Core Web Vitals Monitor is a free Chrome add-on designed for developers, designers, and SEO professionals to track the six Core Web Vitals metrics in real-time while browsing. This tool provides immediate feedback on page performance through color-coded ratings, enabling users to quickly assess loading performance, visual stability, and interactivity. Key metrics include Largest Contentful Paint (LCP), First Contentful Paint (FCP), Time to First Byte (TTFB), Cumulative Layout Shift (CLS), Interaction to Next Paint (INP), and First Input Delay (FID).

The add-on features session grouping by domain for easy comparison across pages, as well as the ability to export metrics in CSV or JSON format for further analysis. Users can also sync data with Google Sheets for historical tracking. With a focus on privacy, all data remains in the user's browser, ensuring no external data transmission is required. LightScout operates without the need for an account and offers a straightforward installation process.