This article was originally published on AI Study Room . For the full version with working code examples and related articles, visit the original post. Best Web Performance Tools 2026: Lighthouse vs WebPageTest vs Sentry vs Checkly Slow sites lose users. But "performance" isn't one thing — it's lab testing, field monitoring, error tracking, and synthetic checks. Lighthouse, WebPageTest, Sentry, and Checkly each cover different parts of the performance puzzle. Here's how to build a complete monitoring stack. Quick Comparison Lighthouse WebPageTest Sentry Checkly Type Lab testing (simulated) Lab testing (real devices) Error tracking + RUM Best for Quick audits, CI integration Deep performance analysis Catching production errors Data source Simulated throttling Real devices, real networks Real user sessions Core Web Vitals Yes (lab only) Yes (lab + field) Yes (RUM — real users) Free tier Free (open source) Free (public tests) Free (5K errors/mo) CI/CD Lighthouse CI WebPageTest API Release tracking Lighthouse —…