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---
title: How to lazy load Client Components and libraries
nav_title: Lazy Loading
description: Lazy load imported libraries and React Components to improve your application's loading performance.
---

{/* The content of this doc is shared between the app and pages router. You can use the `<PagesOnly>Content</PagesOnly>` component to add content that is specific to the Pages Router. Any shared content should not be wrapped in a component. */}

[Lazy loading](https://developer.mozilla.org/docs/Web/Performance/Lazy_loading) in Next.js helps improve the initial loading performance of an application by decreasing the amount of JavaScript needed to render a route.

It allows you to defer loading of **Client Components** and imported libraries, and only include them in the client bundle when they're needed. For example, you might want to defer loading a modal until a user clicks to open it.

There are two ways you can implement lazy loading in Next.js:

1. Using [Dynamic Imports](#nextdynamic) with `next/dynamic`
2. Using [`React.lazy()`](https://react.dev/reference/react/lazy) with [Suspense](https://react.dev/reference/react/Suspense)

By default, Server Components are automatically [code split](https://developer.mozilla.org/docs/Glossary/Code_splitting), and you can use [streaming](/docs/app/api-reference/file-conventions/loading) to progressively send pieces of UI from the server to the client. Lazy loading applies to Client Components.

## `next/dynamic`

`next/dynamic` is a composite of [`React.lazy()`](https://react.dev/reference/react/lazy) and [Suspense](https://react.dev/reference/react/Suspense). It behaves the same way in the `app` and `pages` directories to allow for incremental migration.

## Examples

<AppOnly>
### Importing Client Components

```jsx filename="app/page.js"
'use client'

import { useState } from 'react'
import dynamic from 'next/dynamic'

// Client Components:
const ComponentA = dynamic(() => import('../components/A'))
const ComponentB = dynamic(() => import('../components/B'))
const ComponentC = dynamic(() => import('../components/C'), { ssr: false })

export default function ClientComponentExample() {
  const [showMore, setShowMore] = useState(false)

  return (
    <div>
      {/* Load immediately, but in a separate client bundle */}
      <ComponentA />

      {/* Load on demand, only when/if the condition is met */}
      {showMore && <ComponentB />}
      <button onClick={() => setShowMore(!showMore)}>Toggle</button>

      {/* Load only on the client side */}
      <ComponentC />
    </div>
  )
}
```

> **Note:** When a Server Component dynamically imports a Client Component, automatic [code splitting](https://developer.mozilla.org/docs/Glossary/Code_splitting) is currently **not** supported.

### Skipping SSR

When using `React.lazy()` and Suspense, Client Components will be [prerendered](https://github.com/reactwg/server-components/discussions/4) (SSR) by default.

> **Note:** `ssr: false` option will only work for Client Components, move it into Client Components ensure the client code-splitting working properly.

If you want to disable pre-rendering for a Client Component, you can use the `ssr` option set to `false`:

```jsx
const ComponentC = dynamic(() => import('../components/C'), { ssr: false })
```

### Importing Server Components

If you dynamically import a Server Component, only the Client Components that are children of the Server Component will be lazy-loaded - not the Server Component itself.
It will also help preload the static assets such as CSS when you're using it in Server Components.

```jsx filename="app/page.js"
import dynamic from 'next/dynamic'

// Server Component:
const ServerComponent = dynamic(() => import('../components/ServerComponent'))

export default function ServerComponentExample() {
  return (
    <div>
      <ServerComponent />
    </div>
  )
}
```

> **Note:** `ssr: false` option is not supported in Server Components. You will see an error if you try to use it in Server Components.
> `ssr: false` is not allowed with `next/dynamic` in Server Components. Please move it into a Client Component.

### Loading External Libraries

External libraries can be loaded on demand using the [`import()`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/import) function. This example uses the external library `fuse.js` for fuzzy search. The module is only loaded on the client after the user types in the search input.

```jsx filename="app/page.js"
'use client'

import { useState } from 'react'

const names = ['Tim', 'Joe', 'Bel', 'Lee']

export default function Page() {
  const [results, setResults] = useState()

  return (
    <div>
      <input
        type="text"
        placeholder="Search"
        onChange={async (e) => {
          const { value } = e.currentTarget
          // Dynamically load fuse.js
          const Fuse = (await import('fuse.js')).default
          const fuse = new Fuse(names)

          setResults(fuse.search(value))
        }}
      />
      <pre>Results: {JSON.stringify(results, null, 2)}</pre>
    </div>
  )
}
```

### Adding a custom loading component

```jsx filename="app/page.js"
'use client'

import dynamic from 'next/dynamic'

const WithCustomLoading = dynamic(
  () => import('../components/WithCustomLoading'),
  {
    loading: () => <p>Loading...</p>,
  }
)

export default function Page() {
  return (
    <div>
      {/* The loading component will be rendered while  <WithCustomLoading/> is loading */}
      <WithCustomLoading />
    </div>
  )
}
```

### Importing Named Exports

To dynamically import a named export, you can return it from the Promise returned by [`import()`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/import) function:

```jsx filename="components/hello.js"
'use client'

export function Hello() {
  return <p>Hello!</p>
}
```

```jsx filename="app/page.js"
import dynamic from 'next/dynamic'

const ClientComponent = dynamic(() =>
  import('../components/hello').then((mod) => mod.Hello)
)
```

</AppOnly>

<PagesOnly>

By using `next/dynamic`, the header component will not be included in the page's initial JavaScript bundle. The page will render the Suspense `fallback` first, followed by the `Header` component when the `Suspense` boundary is resolved.

```jsx
import dynamic from 'next/dynamic'

const DynamicHeader = dynamic(() => import('../components/header'), {
  loading: () => <p>Loading...</p>,
})

export default function Home() {
  return <DynamicHeader />
}
```

> **Good to know**: In `import('path/to/component')`, the path must be explicitly written. It can't be a template string nor a variable. Furthermore the `import()` has to be inside the `dynamic()` call for Next.js to be able to match webpack bundles / module ids to the specific `dynamic()` call and preload them before rendering. `dynamic()` can't be used inside of React rendering as it needs to be marked in the top level of the module for preloading to work, similar to `React.lazy`.

## With named exports

To dynamically import a named export, you can return it from the [Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise) returned by [`import()`](https://github.com/tc39/proposal-dynamic-import#example):

```jsx filename="components/hello.js"
export function Hello() {
  return <p>Hello!</p>
}

// pages/index.js
import dynamic from 'next/dynamic'

const DynamicComponent = dynamic(() =>
  import('../components/hello').then((mod) => mod.Hello)
)
```

## With no SSR

To dynamically load a component on the client side, you can use the `ssr` option to disable server-rendering. This is useful if an external dependency or component relies on browser APIs like `window`.

```jsx
'use client'

import dynamic from 'next/dynamic'

const DynamicHeader = dynamic(() => import('../components/header'), {
  ssr: false,
})
```

## With external libraries

This example uses the external library `fuse.js` for fuzzy search. The module is only loaded in the browser after the user types in the search input.

```jsx
import { useState } from 'react'

const names = ['Tim', 'Joe', 'Bel', 'Lee']

export default function Page() {
  const [results, setResults] = useState()

  return (
    <div>
      <input
        type="text"
        placeholder="Search"
        onChange={async (e) => {
          const { value } = e.currentTarget
          // Dynamically load fuse.js
          const Fuse = (await import('fuse.js')).default
          const fuse = new Fuse(names)

          setResults(fuse.search(value))
        }}
      />
      <pre>Results: {JSON.stringify(results, null, 2)}</pre>
    </div>
  )
}
```

</PagesOnly>

	---
	title: How to lazy load Client Components and libraries
	nav_title: Lazy Loading
	description: Lazy load imported libraries and React Components to improve your application's loading performance.
	---

	{/* The content of this doc is shared between the app and pages router. You can use the `<PagesOnly>Content</PagesOnly>` component to add content that is specific to the Pages Router. Any shared content should not be wrapped in a component. */}

	[Lazy loading](https://developer.mozilla.org/docs/Web/Performance/Lazy_loading) in Next.js helps improve the initial loading performance of an application by decreasing the amount of JavaScript needed to render a route.

	It allows you to defer loading of Client Components and imported libraries, and only include them in the client bundle when they're needed. For example, you might want to defer loading a modal until a user clicks to open it.

	There are two ways you can implement lazy loading in Next.js:

	1. Using [Dynamic Imports](#nextdynamic) with `next/dynamic`
	2. Using [`React.lazy()`](https://react.dev/reference/react/lazy) with [Suspense](https://react.dev/reference/react/Suspense)

	By default, Server Components are automatically [code split](https://developer.mozilla.org/docs/Glossary/Code_splitting), and you can use [streaming](/docs/app/api-reference/file-conventions/loading) to progressively send pieces of UI from the server to the client. Lazy loading applies to Client Components.

	## `next/dynamic`

	`next/dynamic` is a composite of [`React.lazy()`](https://react.dev/reference/react/lazy) and [Suspense](https://react.dev/reference/react/Suspense). It behaves the same way in the `app` and `pages` directories to allow for incremental migration.

	## Examples

	<AppOnly>
	### Importing Client Components

	```jsx filename="app/page.js"
	'use client'

	import { useState } from 'react'
	import dynamic from 'next/dynamic'

	// Client Components:
	const ComponentA = dynamic(() => import('../components/A'))
	const ComponentB = dynamic(() => import('../components/B'))
	const ComponentC = dynamic(() => import('../components/C'), { ssr: false })

	export default function ClientComponentExample() {
	const [showMore, setShowMore] = useState(false)

	return (
	<div>
	{/* Load immediately, but in a separate client bundle */}
	<ComponentA />

	{/* Load on demand, only when/if the condition is met */}
	{showMore && <ComponentB />}
	<button onClick={() => setShowMore(!showMore)}>Toggle</button>

	{/* Load only on the client side */}
	<ComponentC />
	</div>
	)
	}
	```

	> Note: When a Server Component dynamically imports a Client Component, automatic [code splitting](https://developer.mozilla.org/docs/Glossary/Code_splitting) is currently not supported.

	### Skipping SSR

	When using `React.lazy()` and Suspense, Client Components will be [prerendered](https://github.com/reactwg/server-components/discussions/4) (SSR) by default.

	> Note: `ssr: false` option will only work for Client Components, move it into Client Components ensure the client code-splitting working properly.

	If you want to disable pre-rendering for a Client Component, you can use the `ssr` option set to `false`:

	```jsx
	const ComponentC = dynamic(() => import('../components/C'), { ssr: false })
	```

	### Importing Server Components

	If you dynamically import a Server Component, only the Client Components that are children of the Server Component will be lazy-loaded - not the Server Component itself.
	It will also help preload the static assets such as CSS when you're using it in Server Components.

	```jsx filename="app/page.js"
	import dynamic from 'next/dynamic'

	// Server Component:
	const ServerComponent = dynamic(() => import('../components/ServerComponent'))

	export default function ServerComponentExample() {
	return (
	<div>
	<ServerComponent />
	</div>
	)
	}
	```

	> Note: `ssr: false` option is not supported in Server Components. You will see an error if you try to use it in Server Components.
	> `ssr: false` is not allowed with `next/dynamic` in Server Components. Please move it into a Client Component.

	### Loading External Libraries

	External libraries can be loaded on demand using the [`import()`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/import) function. This example uses the external library `fuse.js` for fuzzy search. The module is only loaded on the client after the user types in the search input.

	```jsx filename="app/page.js"
	'use client'

	import { useState } from 'react'

	const names = ['Tim', 'Joe', 'Bel', 'Lee']

	export default function Page() {
	const [results, setResults] = useState()

	return (
	<div>
	<input
	type="text"
	placeholder="Search"
	onChange={async (e) => {
	const { value } = e.currentTarget
	// Dynamically load fuse.js
	const Fuse = (await import('fuse.js')).default
	const fuse = new Fuse(names)

	setResults(fuse.search(value))
	}}
	/>
	<pre>Results: {JSON.stringify(results, null, 2)}</pre>
	</div>
	)
	}
	```

	### Adding a custom loading component

	```jsx filename="app/page.js"
	'use client'

	import dynamic from 'next/dynamic'

	const WithCustomLoading = dynamic(
	() => import('../components/WithCustomLoading'),
	{
	loading: () => <p>Loading...</p>,
	}
	)

	export default function Page() {
	return (
	<div>
	{/* The loading component will be rendered while <WithCustomLoading/> is loading */}
	<WithCustomLoading />
	</div>
	)
	}
	```

	### Importing Named Exports

	To dynamically import a named export, you can return it from the Promise returned by [`import()`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Operators/import) function:

	```jsx filename="components/hello.js"
	'use client'

	export function Hello() {
	return <p>Hello!</p>
	}
	```

	```jsx filename="app/page.js"
	import dynamic from 'next/dynamic'

	const ClientComponent = dynamic(() =>
	import('../components/hello').then((mod) => mod.Hello)
	)
	```

	</AppOnly>

	<PagesOnly>

	By using `next/dynamic`, the header component will not be included in the page's initial JavaScript bundle. The page will render the Suspense `fallback` first, followed by the `Header` component when the `Suspense` boundary is resolved.

	```jsx
	import dynamic from 'next/dynamic'

	const DynamicHeader = dynamic(() => import('../components/header'), {
	loading: () => <p>Loading...</p>,
	})

	export default function Home() {
	return <DynamicHeader />
	}
	```

	> Good to know: In `import('path/to/component')`, the path must be explicitly written. It can't be a template string nor a variable. Furthermore the `import()` has to be inside the `dynamic()` call for Next.js to be able to match webpack bundles / module ids to the specific `dynamic()` call and preload them before rendering. `dynamic()` can't be used inside of React rendering as it needs to be marked in the top level of the module for preloading to work, similar to `React.lazy`.

	## With named exports

	To dynamically import a named export, you can return it from the [Promise](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Promise) returned by [`import()`](https://github.com/tc39/proposal-dynamic-import#example):

	```jsx filename="components/hello.js"
	export function Hello() {
	return <p>Hello!</p>
	}

	// pages/index.js
	import dynamic from 'next/dynamic'

	const DynamicComponent = dynamic(() =>
	import('../components/hello').then((mod) => mod.Hello)
	)
	```

	## With no SSR

	To dynamically load a component on the client side, you can use the `ssr` option to disable server-rendering. This is useful if an external dependency or component relies on browser APIs like `window`.

	```jsx
	'use client'

	import dynamic from 'next/dynamic'

	const DynamicHeader = dynamic(() => import('../components/header'), {
	ssr: false,
	})
	```

	## With external libraries

	This example uses the external library `fuse.js` for fuzzy search. The module is only loaded in the browser after the user types in the search input.

	```jsx
	import { useState } from 'react'

	const names = ['Tim', 'Joe', 'Bel', 'Lee']

	export default function Page() {
	const [results, setResults] = useState()

	return (
	<div>
	<input
	type="text"
	placeholder="Search"
	onChange={async (e) => {
	const { value } = e.currentTarget
	// Dynamically load fuse.js
	const Fuse = (await import('fuse.js')).default
	const fuse = new Fuse(names)

	setResults(fuse.search(value))
	}}
	/>
	<pre>Results: {JSON.stringify(results, null, 2)}</pre>
	</div>
	)
	}
	```

	</PagesOnly>