Understanding Web Performance Metrics and Core Web Vitals

Introduction

This article explains how to measure website performance using various metrics and introduces Core Web Vitals as key indicators for user experience.

Performance Metrics

The article discusses four categories of performance metrics: whether the navigation occurs, if the content is useful, if the page is usable, and if the interaction is pleasant. It details metrics like TTFB, FP, FCP, LCP, FID, TBT, and CLS.

Core Web Vitals

Core Web Vitals are a subset of Web Vitals focusing on LCP, FID, and CLS. These metrics are designed to provide a unified way to measure user experience, with thresholds set for each to ensure good performance.

Tools and Resources

The article lists tools like Search Console, PageSpeed Insights, Lighthouse, and Chrome DevTools to measure and improve Core Web Vitals.

References

[1] Web performance made easy (Google I/O '18)

[2] FMP, TTI, WTF? Making Sense of Web Performance

[3] User-centric performance metrics

[4] Response Times: The 3 Important Limits

[5] Understanding Cumulative Layout Shift

[6] Defining the Core Web Vitals metrics thresholds

[7] Tools to measure Core Web Vitals