Chapter 8 · Practice 2 of 4
Keep StrictMode on for the whole app in development
From Project hygiene
Why it matters
Wrapping your app in <StrictMode> adds checks that run only in development:
- components render twice,
- effects run twice,
- deprecated APIs trigger warnings.
These checks surface impure components and missing effect cleanups early, when they are cheap to fix. Frameworks like Next.js enable it by default.