REACT PERFORMANCE ENGINEERING · MODULE 01 · MEASURING PERFORMANCE
1.11.3

LESSON 1.2

Core Web Vitals in a React app

14:46·7,037 learners
Mira KovacMira Kovac
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In this lesson you will

  • Interpret LCP, INP, and CLS in practical terms
  • Separate lab data from field data
  • Attribute a poor score to a specific element or interaction

Lab numbers on your laptop are not what users experience. Vitals give you a field measure of loading, responsiveness, and visual stability.

What this lesson covers

  • Interpret LCP, INP, and CLS in practical terms
  • Separate lab data from field data
  • Attribute a poor score to a specific element or interaction

This lesson sits in Measuring Performance, part of React Performance Engineering. It assumes what came before it and leads directly into the next lesson in the module.

PRO TIP

A good score on your machine means very little. Look at the field data from real devices.

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1.3 · Finding wasted renders

09:18

React Performance Engineering

8%
1.1 Profiling with React DevTools12:581.2 Core Web Vitals in a React app14:461.3 Finding wasted renders09:18

Every lesson, searchable to the second.

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