React-Performance

A passing Lighthouse score today doesn't mean your app stays fast tomorrow. Here's how to catch performance regressions automatically, before they reach production.

Hydration warnings and hydration slowness are two different problems with different fixes. This guide walks through diagnosing which one you have, then resolving it step by step.

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.

Fiber changed how React schedules and interrupts rendering work. Here are the real questions developers ask when trying to understand what it does and why it matters for performance.

State management libraries aren't interchangeable performance-wise. Here is a symptom-to-fix checklist for diagnosing slow global state in React apps.

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.

A dashboard was loading its panels one after another instead of all at once. Here is how we traced the waterfall and rebuilt the data layer around Suspense.