React

Say you are trying to figure out why real users report a sluggish React app while your local Lighthouse scores look fine. Here is how RUM data closes that gap.

Chrome's own data shows most slow interactions aren't caused by the work you'd expect. Here are the five most common INP culprits in React apps, ranked by how much they typically cost you.

By the end of this guide, you'll know exactly where CSS-in-JS libraries spend their runtime cost, how to measure it in your own app, and when switching approaches is actually worth the effort.

A memory leak in React is not the same thing as a slow render. Here is a troubleshooting checklist for the most common causes, with symptoms, root causes, and fixes.

Lighthouse scores get chased, misread, and dismissed in equal measure. Here's what the audit actually measures and how to use it correctly on a React app.

Custom hooks look like plain functions, but they carry hidden performance costs. Here's how beginner-level hook code differs from the patterns experienced React developers reach for.

Long tasks, blocked main threads, and sluggish interactions usually trace back to JavaScript execution time. Here are the practical questions to ask when you're diagnosing this in a React app.

Lighthouse scores and real-user Core Web Vitals often disagree, sometimes by a wide margin. Here's what the data shows about measuring performance correctly in React.

I'm often asked whether to use CSS or a library like Framer Motion for React animations. Here's the 3-step decision process I use to guarantee a smooth 60fps.

I've seen React apps grind to a halt during heavy computations. The problem isn't React, it's the single-threaded nature of JavaScript. Here's how we use Web Workers to fix it.