How does streaming SSR with Suspense work in Next.js?

How does streaming SSR with Suspense work in Next.js? · IT Interview Practice

tsx

import { Suspense } from "react";

export default function Page() {
  return (
    <>
      <Header />                          {/* sent immediately */}
      <Suspense fallback={<Skeleton />}>  {/* streams independently */}
        <SlowProductList />               {/* an async Server Component */}
      </Suspense>
      <Footer />                          {/* sent immediately */}
    </>
  );
}

async function SlowProductList() {
  const products = await getProducts();   // takes 2s — doesn't block the rest
  return <List products={products} />;
}

text

TTFB (Time To First Byte) ↓ — server sends the shell right away
FCP (First Contentful Paint) ↓ — visible content appears sooner
User perceives the page as fast even if some data is slow

How does streaming SSR with Suspense work in Next.js?

The problem streaming solves

Using Suspense to stream

loading.tsx is automatic Suspense

Why streaming helps the key metrics

Why it matters

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