Calibre RUM captures Core Web Vitals from real browser sessions, giving you depth and clarity. Available now on all plans.

Calibre Blog provides insights, tutorials, and updates on web performance optimization, front-end development, and website monitoring. Covering topics such as performance metrics, image optimization, and page speed analysis, Calibre Blog offers resources for developers and webmasters. Readers can learn about improving website performance, diagnosing performance issues, and optimizing user experience through Calibre's articles and performance optimization guides.

Calibre

Calibre has launched Real User Monitoring (RUM) on all plans, including the free trial. Unlike competitors' sprawling APM products, Calibre RUM is designed to be focused, privacy-first, and lightweight. It captures Core Web Vitals and UX signals from anonymized browser sessions, ranks pages by traffic and impact, provides element-level attribution (identifying specific DOM elements causing poor LCP, INP, or CLS), and segments audience data by country, device, browser, and OS. RUM complements Calibre's existing synthetic and CrUX monitoring, giving teams three data sources for web performance. Setup requires a single script tag, with predictable session-based pricing starting at 5,000 sessions per month.

Real User Monitoring: Focus, depth, and clarity from real browser sessions

Fast websites don’t just happen by themselves #