What is Streaming in Next.js: How It Works and When to Use

In Next.js, streaming means sending parts of a page to the browser as soon as they are ready instead of waiting for the whole page to finish loading. This helps users see content faster and improves the overall experience by loading the page in chunks.

How It Works

Streaming in Next.js works like serving a meal in courses rather than all at once. Instead of waiting for the entire page to be ready, Next.js sends pieces of the page to the browser as soon as they are prepared. This means the user can start seeing and interacting with parts of the page immediately while the rest is still loading.

Under the hood, Next.js uses React Server Components and the React 18 streaming feature to send HTML chunks progressively. This reduces waiting time and makes the page feel faster and more responsive, especially for large or complex pages.

Example

This example shows a Next.js server component that streams content in parts. The first part renders immediately, and the second part simulates a delay before streaming.

jsx

import React, { Suspense } from 'react';

function DelayedContent() {
  const [ready, setReady] = React.useState(false);
  React.useEffect(() => {
    const timer = setTimeout(() => setReady(true), 3000);
    return () => clearTimeout(timer);
  }, []);

  if (!ready) return <p>Loading delayed content...</p>;
  return <p>Delayed content loaded!</p>;
}

export default function StreamingPage() {
  return (
    <main>
      <h1>Streaming in Next.js Example</h1>
      <p>This content loads immediately.</p>
      <Suspense fallback={<p>Loading delayed content...</p>}>
        <DelayedContent />
      </Suspense>
    </main>
  );
}

Output

Streaming in Next.js Example
This content loads immediately.
Loading delayed content...
(After 3 seconds) Delayed content loaded!

When to Use

Streaming is useful when your page has parts that take different times to load, like fetching data from slow APIs or rendering large components. It helps users start interacting with the page faster instead of staring at a blank screen.

Real-world uses include news sites loading headlines first, e-commerce pages showing product info before reviews, or dashboards displaying key stats immediately while loading detailed charts.

Key Points

• Streaming sends page parts to the browser as soon as they are ready.
• It improves perceived loading speed and user experience.
• Next.js uses React 18 features like Suspense and Server Components for streaming.
• Best for pages with slow or large content sections.

Key Takeaways

Streaming in Next.js sends page chunks progressively to speed up loading.

It uses React 18 features like Suspense and Server Components.

Use streaming when parts of your page take different times to load.

Streaming improves user experience by showing content faster.

It is ideal for complex pages with slow data or heavy components.