What tools are used for analysis?

Tools for analyzing site performance fall into 2 types: online services and devtools / CI integrations. Here are the main ones:

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#Browser tools

• Chrome DevTools → Performance tab Records and visualizes page behavior (timelines, blocking, layout, paint, GC, and so on)
• Chrome DevTools → Lighthouse Scores the site on metrics (LCP, FID, CLS, TBT, and others) and gives recommendations.
• Web Vitals Extension Shows real metrics (LCP, CLS, FID) in real time right in the browser.

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#Online services

• PageSpeed Insights From Google. Analyzes both real user data (CrUX) and simulated performance.
• WebPageTest Gives a very detailed picture: waterfall, filmstrip, thread blocking, TTI, visual progress, and so on.
• GTmetrix A more visual interface for analyzing loading speed and recommendations.

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#Automation and CI tools

• Lighthouse CI Automated site audit in CI/CD. Lets you set a performance budget and fail the build on violations.
• Web Vitals Reporters Connect to real traffic (via JS) and send metrics (LCP, FID, CLS) to analytics (for example, GA, BigQuery).
• Sitespeed.io An open source tool for integrating Lighthouse, WebPageTest, and analyzing large volumes of pages.

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#Third-party profilers / add-ons

• Perfume.js A JS library for collecting web vitals directly in users' browsers.
• Calibre, SpeedCurve, Treo Paid tools for monitoring performance over time, with version comparison, alerts, and real-time metrics.

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Conclusion: If you are testing locally → DevTools + Lighthouse. If you are checking production → PageSpeed Insights + Web Vitals. If you are automating → Lighthouse CI + Web Vitals Reporter.