A Practical React Performance Checklist

Sample post — replace with your own. A pragmatic, no-nonsense checklist.

Most React performance advice is premature. Here's the short list I actually reach for, roughly in order of impact.

1. Measure first

Open the Profiler. Find the component that re-renders most and costs most. Optimize that. Everything below is wasted effort without this step.

2. Fix the render, not the memo

memo and useMemo are patches. Often the real fix is:

• Moving state down so fewer components re-render.
• Splitting a fat context into smaller ones.
• Passing stable references.

3. Virtualize long lists

If you render 1,000 rows, render 20 and virtualize the rest.

4. Ship less JavaScript

Code-split routes, lazy-load heavy components, and audit your bundle. The fastest component is the one you never sent.

Closing

Performance is a habit of measurement, not a bag of tricks.