Next.js Server vs Client Components

What are Server Components?

Server Components are React components that run on the server and are not sent to the browser. This means they are not included in the JavaScript bundle sent to the client, reducing the size of the client-side code and improving performance.

Server Components can fetch data directly from the server, access databases, and perform server-side logic without exposing this code to the client. They are ideal for rendering static content, fetching data, and performing server-side operations.

This Means

• Code executes on the server
• Only HTML is sent to the browser
• No unnecessary JavaScript is sent to the client

This improves application performance, SEO and reduces the amount of JavaScript sent to the client.

Example of Server Component

Here is an example of a simple Server Component:

// app/server-component.tsx
export default function ServerComponent() {
  return (
    <div>
      <h2>This is a Server Component</h2>
      <p>It runs on the server and is not sent to the browser.</p>
    </div>
  );
}

Key features of Server Components

• Server-only execution: Server Components run only on the server and are not sent to the browser.
• Smaller client-side bundles: Since they are not sent to the browser, they reduce the size of client-side JavaScript.
• Secure data handling: Sensitive data and logic remain on the server, enhancing security.
• Server-side rendering: Server Components can be rendered on the server before being sent to the client.
• Direct access to server resources: Server Components can directly access server-side resources like databases and file systems.

What are Client Components?

Client Components are React components that run on the client (browser) and are sent to the browser as JavaScript. They are responsible for handling user interactions, managing state, and rendering UI elements that require client-side behavior.

Client Components can use React hooks, manage state, and handle events. They are ideal for interactive UI elements, forms, and components that require client-side logic.

Key features of Client Components

• Client-side execution: Client Components run only in the browser.
• Interactive UI: They handle user interactions and manage component state.
• React hooks support: They can use React hooks like useState, useEffect, etc.
• Event handling: They can handle events like clicks, form submissions, etc.

Example of Client Component

// app/client-component.tsx
'use client';
import { useState } from 'react';

export default function ClientComponent() {
  const [count, setCount] = useState(0);
  return (
    <div>
      <h2>This is a Client Component</h2>
      <p>Count: {count}</p>
      <button onClick={() => setCount(count + 1)}>Increment</button>
    </div>
  );
}

When to Use Server Components and Client Components

Use Server Components when you want to render static content, fetch data from the server, or perform server-side logic. They are ideal for components that do not require client-side interactivity.

Use Client Components when you need to handle user interactions, manage state, or implement client-side logic. They are essential for building interactive UI elements and components that require client-side behavior.

Use Server Components when you want to render static content, fetch data from the server, or perform server-side logic. They are ideal for components that do not require client-side interactivity.

Use Client Components when you need to handle user interactions, manage state, or implement client-side logic. They are essential for building interactive UI elements and components that require client-side behavior.

Server Component vs Client Component

When to use Server Components

Use Server Components when you want to render static content, fetch data from the server, or perform server-side logic. They are ideal for components that do not require client-side interactivity.

1. Fetching data from API
2. Fetching data from database
3. Static content
4. SEO content
5. Non-interactive UI

Examples

1. Blog pages
2. Product pages
3. Landing pages

When to use Client Components

Use Client Components when you need to handle user interactions, manage state, or implement client-side logic. They are essential for building interactive UI elements and components that require client-side behavior.

1. Forms
2. Buttons
3. Interactive UI
4. Event handling
5. State management

Example

1. Counter
2. Login form
3. Dashboard interaction

Using Client Component inside Server Component

You can use Client Components inside Server Components to create interactive UI elements while still benefiting from server-side rendering for the rest of the component. This allows you to optimize performance while providing a rich user experience.

Example

// app/client-component.tsx
'use client';

export default function Button() {
  return <button>Click Me</button>;
}

// app/server-component.tsx
import Button from './client-component';

export default function ServerComponent() {
  return (
    <div>
      <h2>This is a Server Component</h2>
      <Button />
    </div>
  );}

FAQ: Next.js Server vs Client Components

Summary: Key Takeaways

• Use Server Components for static content, data fetching, and SEO optimization in Next.js.
• Use Client Components for interactivity, state, and client-side logic.
• Combining both types allows you to build fast, SEO-friendly, and interactive applications.
• Choosing the right component type improves performance, reduces bundle size, and enhances user experience.