React Best Practices

What this best practices guide is

A practical guide to writing React the way the React team recommends today. It covers components and purity, state, effects, performance with React Compiler, React 19 form actions, accessibility, testing and project hygiene, with short examples you can copy.

It has 8 chapters and 36 practices, each with why it matters, what to do and what to avoid. For frontend developers.

Chapter by chapter

1. Components and purity (5 practices)

How to shape components so React can render, re-render and optimize them safely. Purity is the rule everything else depends on.

2. State and data flow (5 practices)

Where state should live, how much of it you need, and how to update it so React notices. Most re-render bugs start here.

3. Effects, and when you do not need one (4 practices)

Effects are an escape hatch for syncing with systems outside React. This chapter shows when to use one and the common cases where you should not.

4. Performance and memoization (5 practices)

How to keep React fast in 2026: let React Compiler memoize, measure before you optimize, and keep urgent updates responsive.

5. Forms and actions in React 19 (5 practices)

React 19 Actions handle pending state, errors and form resets for you. This chapter shows the hooks to use and how to keep mutations safe.

6. Accessibility (4 practices)

React does not make an app accessible on its own. These practices cover semantic markup, labels, focus and how to check your work.

7. Testing React code (4 practices)

Tests that give you confidence to refactor: test what users see and do, not how components are built inside.

8. Project hygiene (4 practices)

Habits that keep a React codebase easy to work in as it grows: types, structure, Strict Mode and staying current.

How it works on Sefism

The guide reads like a short course: a syllabus, then one chapter per page in a focused reader, with a quiz at the end of each chapter for members. Every chapter is open to everyone.

Every claim is checked against the sources listed on the page (7 cited).