Calibre

About Calibre

Calibre is an end-to-end web performance monitoring and analytics platform that combines synthetic testing with real-user data from Chrome User Experience Report (CrUX). It enables teams to track Core Web Vitals, run Google Lighthouse audits, set performance budgets, and catch speed regressions before they reach production through GitHub Pull Request Reviews. With testing infrastructure across 17 global locations, Calibre provides a comprehensive view of how websites perform for users worldwide. The platform is designed for collaborative use across entire organizations. Teams can simulate different devices, connection speeds, and locations using Test Profiles, monitor unlimited sites and URLs on any plan, and get automated insights delivered via email reports. Third-party tracking identifies external scripts that slow down pages, while the AI-powered test verification engine automatically re-tests anomalous results to reduce false positives. Calibre integrates with developer workflows through its CLI, Node.js API, webhooks, and native Vercel and Netlify integrations for automatic deploy tracking. All data is encrypted at rest, retained for the lifetime of your account, and the platform maintains 99.91% uptime with full GDPR compliance.