Modern React Best Practices for 2025

React has evolved significantly over the past few years. With the introduction of Server Components, improved data-fetching patterns, and a stronger focus on performance and developer experience, writing modern React in 2025 looks very different from the React of 2018.

This guide highlights the most important best practices for building scalable, maintainable, and high-performance React applications today.

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1. Prefer Server Components by Default

Server Components are now a core part of the React ecosystem, especially when using frameworks like Next.js App Router.

Why Server Components matter:

• Smaller client bundles
• Faster initial page loads
• No unnecessary hydration
• Secure access to server-only logic (databases, secrets)

Best practice:

• Treat Server Components as the default
• Use Client Components only when you need interactivity

// Server Component (default)
export default async function ProductsPage() {
  const products = await getProducts();
  return <ProductList products={products} />;
}

Use "use client" sparingly, and only at the leaf nodes where interactivity is required.

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2. Co-locate Data Fetching with UI

Global data-fetching layers and massive useEffect trees are no longer the norm.

Modern React favors co-location:

• Fetch data as close as possible to where it’s rendered
• Keep components predictable and easy to reason about

export default async function UserProfile({ id }: { id: string }) {
  const user = await getUser(id);
  return <ProfileCard user={user} />;
}

This approach:

• Improves readability
• Simplifies debugging
• Eliminates unnecessary prop drilling

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3. Use Zod or Valibot for Runtime Validation

TypeScript is powerful, but it only works at compile time. In 2025, runtime validation is no longer optional.

Recommended tools:

• Zod
• Valibot

They provide:

• Runtime safety
• Schema-driven validation
• Strong TypeScript inference

const UserSchema = z.object({
  id: z.string(),
  email: z.string().email(),
});

Use schemas for:

• API responses
• Form validation
• Server actions
• Environment variables

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4. Embrace Server Actions Instead of API Routes

Server Actions simplify the mental model of client-server communication.

Benefits:

• No manual API endpoints
• Automatic serialization
• Built-in security
• Less boilerplate

"use server";

export async function createPost(data: FormData) {
  // server-only logic
}

Pair Server Actions with form submissions or mutations for a cleaner architecture.

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5. Keep Client Components Small and Focused

Client Components are expensive — they increase bundle size and hydration cost.

Best practices:

• Keep Client Components shallow
• Avoid importing large libraries into them
• Split logic into hooks when needed

"use client";

export function ToggleButton() {
  const [open, setOpen] = useState(false);
  return <button onClick={() => setOpen(!open)}>Toggle</button>;
}

If a component doesn’t need state, effects, or browser APIs — it shouldn’t be a Client Component.

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6. Favor Composition Over Props Explosion

Passing too many props is a code smell.

Instead:

• Use component composition
• Leverage children
• Create small, reusable primitives

<Card>
  <CardHeader />
  <CardContent />
</Card>

This leads to:

• Cleaner APIs
• Better reusability
• Easier refactoring

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7. Avoid Premature State Management

In 2025, many apps don’t need global state libraries.

Before reaching for Redux or Zustand, consider:

• Server Components
• URL state
• React context
• Local component state

When global state is required:

• Prefer Redux Toolkit, Zustand, or Jotai
• Keep state minimal and domain-focused

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8. Optimize Performance with Intentional Memoization

useMemo and useCallback are not default tools.

Use them only when:

• You have measurable performance issues
• You’re preventing unnecessary renders in large trees

Blind memoization often:

• Adds complexity
• Makes code harder to read
• Provides no real benefit

Measure first. Optimize second.

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9. Use TypeScript Strict Mode

Strict TypeScript is no longer optional for serious projects.

Enable:

• strict
• noUncheckedIndexedAccess
• exactOptionalPropertyTypes

This leads to:

• Fewer runtime bugs
• Better editor tooling
• Safer refactors

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10. Write Tests That Reflect User Behavior

Modern testing focuses on what users see and do, not implementation details.

Recommended stack:

• @testing-library/react
• @testing-library/user-event
• Jest or Vitest

Test:

• Critical flows
• Edge cases
• Data rendering
• Error states

Avoid testing:

• Internal hooks
• Private functions
• Framework internals

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Final Thoughts

React in 2025 is:

• More server-first
• More intentional
• Less boilerplate-heavy

The best React code today is:

• Easy to read
• Easy to delete
• Easy to scale

Focus on clarity over cleverness, and let the framework do the heavy lifting.