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---
title: How to upgrade to version 15
nav_title: Version 15
description: Upgrade your Next.js Application from Version 14 to 15.
---

{/* 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. */}

## Upgrading from 14 to 15

To update to Next.js version 15, you can use the `upgrade` codemod:

```bash filename="Terminal"
npx @next/codemod@canary upgrade latest
```

If you prefer to do it manually, ensure that you're installing the latest Next & React versions:
```bash filename="Terminal"
npm i next@latest react@latest react-dom@latest eslint-config-next@latest
```
> **Good to know:**
>
> - If you see a peer dependencies warning, you may need to update `react` and `react-dom` to the suggested versions, or use the `--force` or `--legacy-peer-deps` flag to ignore the warning. This won't be necessary once both Next.js 15 and React 19 are stable.

## React 19

- The minimum versions of `react` and `react-dom` is now 19.
- `useFormState` has been replaced by `useActionState`. The `useFormState` hook is still available in React 19, but it is deprecated and will be removed in a future release. `useActionState` is recommended and includes additional properties like reading the `pending` state directly. [Learn more](https://react.dev/reference/react/useActionState).
- `useFormStatus` now includes additional keys like `data`, `method`, and `action`. If you are not using React 19, only the `pending` key is available. [Learn more](https://react.dev/reference/react-dom/hooks/useFormStatus).
- Read more in the [React 19 upgrade guide](https://react.dev/blog/2024/04/25/react-19-upgrade-guide).

> **Good to know:** If you are using TypeScript, ensure you also upgrade `@types/react` and `@types/react-dom` to their latest versions.

## Async Request APIs (Breaking change)

Previously synchronous Dynamic APIs that rely on runtime information are now **asynchronous**:

- [`cookies`](/docs/app/api-reference/functions/cookies)
- [`headers`](/docs/app/api-reference/functions/headers)
- [`draftMode`](/docs/app/api-reference/functions/draft-mode)
- `params` in [`layout.js`](/docs/app/api-reference/file-conventions/layout), [`page.js`](/docs/app/api-reference/file-conventions/page), [`route.js`](/docs/app/api-reference/file-conventions/route), [`default.js`](/docs/app/api-reference/file-conventions/default), [`opengraph-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image), [`twitter-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image), [`icon`](/docs/app/api-reference/file-conventions/metadata/app-icons), and [`apple-icon`](/docs/app/api-reference/file-conventions/metadata/app-icons).
- `searchParams` in [`page.js`](/docs/app/api-reference/file-conventions/page)

To ease the burden of migration, a [codemod is available](/docs/app/guides/upgrading/codemods#150) to automate the process and the APIs can temporarily be accessed synchronously.

### `cookies`

#### Recommended Async Usage

```tsx
import { cookies } from 'next/headers'
// Before
const cookieStore = cookies()
const token = cookieStore.get('token')
// After
const cookieStore = await cookies()
const token = cookieStore.get('token')
```

#### Temporary Synchronous Usage

```tsx filename="app/page.tsx" switcher
import { cookies, type UnsafeUnwrappedCookies } from 'next/headers'
// Before
const cookieStore = cookies()
const token = cookieStore.get('token')
// After
const cookieStore = cookies() as unknown as UnsafeUnwrappedCookies
// will log a warning in dev
const token = cookieStore.get('token')
```

```jsx filename="app/page.js" switcher
import { cookies } from 'next/headers'
// Before
const cookieStore = cookies()
const token = cookieStore.get('token')
// After
const cookieStore = cookies()
// will log a warning in dev
const token = cookieStore.get('token')
```

### `headers`

#### Recommended Async Usage

```tsx
import { headers } from 'next/headers'
// Before
const headersList = headers()
const userAgent = headersList.get('user-agent')
// After
const headersList = await headers()
const userAgent = headersList.get('user-agent')
```

#### Temporary Synchronous Usage

```tsx filename="app/page.tsx" switcher
import { headers, type UnsafeUnwrappedHeaders } from 'next/headers'
// Before
const headersList = headers()
const userAgent = headersList.get('user-agent')
// After
const headersList = headers() as unknown as UnsafeUnwrappedHeaders
// will log a warning in dev
const userAgent = headersList.get('user-agent')
```

```jsx filename="app/page.js" switcher
import { headers } from 'next/headers'
// Before
const headersList = headers()
const userAgent = headersList.get('user-agent')
// After
const headersList = headers()
// will log a warning in dev
const userAgent = headersList.get('user-agent')
```

### `draftMode`

#### Recommended Async Usage

```tsx
import { draftMode } from 'next/headers'
// Before
const { isEnabled } = draftMode()
// After
const { isEnabled } = await draftMode()
```

#### Temporary Synchronous Usage

```tsx filename="app/page.tsx" switcher
import { draftMode, type UnsafeUnwrappedDraftMode } from 'next/headers'
// Before
const { isEnabled } = draftMode()
// After
// will log a warning in dev
const { isEnabled } = draftMode() as unknown as UnsafeUnwrappedDraftMode
```

```jsx filename="app/page.js" switcher
import { draftMode } from 'next/headers'
// Before
const { isEnabled } = draftMode()
// After
// will log a warning in dev
const { isEnabled } = draftMode()
```

### `params` & `searchParams`

#### Asynchronous Layout

```tsx filename="app/layout.tsx" switcher
// Before
type Params = { slug: string }
export function generateMetadata({ params }: { params: Params }) {
  const { slug } = params
}
export default async function Layout({
  children,
  params,
}: {
  children: React.ReactNode
  params: Params
}) {
  const { slug } = params
}
// After
type Params = Promise<{ slug: string }>
export async function generateMetadata({ params }: { params: Params }) {
  const { slug } = await params
}
export default async function Layout({
  children,
  params,
}: {
  children: React.ReactNode
  params: Params
}) {
  const { slug } = await params
}
```

```jsx filename="app/layout.js" switcher
// Before
export function generateMetadata({ params }) {
  const { slug } = params
}
export default async function Layout({ children, params }) {
  const { slug } = params
}
// After
export async function generateMetadata({ params }) {
  const { slug } = await params
}
export default async function Layout({ children, params }) {
  const { slug } = await params
}
```

#### Synchronous Layout

```tsx filename="app/layout.tsx" switcher
// Before
type Params = { slug: string }
export default function Layout({
  children,
  params,
}: {
  children: React.ReactNode
  params: Params
}) {
  const { slug } = params
}
// After
import { use } from 'react'
type Params = Promise<{ slug: string }>
export default function Layout(props: {
  children: React.ReactNode
  params: Params
}) {
  const params = use(props.params)
  const slug = params.slug
}
```

```jsx filename="app/layout.js" switcher
// Before
export default function Layout({ children, params }) {
  const { slug } = params
}
// After
import { use } from 'react'
export default async function Layout(props) {
  const params = use(props.params)
  const slug = params.slug
}
```

#### Asynchronous Page

```tsx filename="app/page.tsx" switcher
// Before
type Params = { slug: string }
type SearchParams = { [key: string]: string | string[] | undefined }
export function generateMetadata({
  params,
  searchParams,
}: {
  params: Params
  searchParams: SearchParams
}) {
  const { slug } = params
  const { query } = searchParams
}
export default async function Page({
  params,
  searchParams,
}: {
  params: Params
  searchParams: SearchParams
}) {
  const { slug } = params
  const { query } = searchParams
}
// After
type Params = Promise<{ slug: string }>
type SearchParams = Promise<{ [key: string]: string | string[] | undefined }>
export async function generateMetadata(props: {
  params: Params
  searchParams: SearchParams
}) {
  const params = await props.params
  const searchParams = await props.searchParams
  const slug = params.slug
  const query = searchParams.query
}
export default async function Page(props: {
  params: Params
  searchParams: SearchParams
}) {
  const params = await props.params
  const searchParams = await props.searchParams
  const slug = params.slug
  const query = searchParams.query
}
```

```jsx filename="app/page.js" switcher
// Before
export function generateMetadata({ params, searchParams }) {
  const { slug } = params
  const { query } = searchParams
}
export default function Page({ params, searchParams }) {
  const { slug } = params
  const { query } = searchParams
}
// After
export async function generateMetadata(props) {
  const params = await props.params
  const searchParams = await props.searchParams
  const slug = params.slug
  const query = searchParams.query
}
export async function Page(props) {
  const params = await props.params
  const searchParams = await props.searchParams
  const slug = params.slug
  const query = searchParams.query
}
```

#### Synchronous Page

```tsx
'use client'
// Before
type Params = { slug: string }
type SearchParams = { [key: string]: string | string[] | undefined }
export default function Page({
  params,
  searchParams,
}: {
  params: Params
  searchParams: SearchParams
}) {
  const { slug } = params
  const { query } = searchParams
}
// After
import { use } from 'react'
type Params = Promise<{ slug: string }>
type SearchParams = Promise<{ [key: string]: string | string[] | undefined }>
export default function Page(props: {
  params: Params
  searchParams: SearchParams
}) {
  const params = use(props.params)
  const searchParams = use(props.searchParams)
  const slug = params.slug
  const query = searchParams.query
}
```

```jsx
// Before
export default function Page({ params, searchParams }) {
  const { slug } = params
  const { query } = searchParams
}
// After
import { use } from "react"
export default function Page(props) {
  const params = use(props.params)
  const searchParams = use(props.searchParams)
  const slug = params.slug
  const query = searchParams.query
}
```

#### Route Handlers

```tsx filename="app/api/route.ts" switcher
// Before
type Params = { slug: string }
export async function GET(request: Request, segmentData: { params: Params }) {
  const params = segmentData.params
  const slug = params.slug
}
// After
type Params = Promise<{ slug: string }>
export async function GET(request: Request, segmentData: { params: Params }) {
  const params = await segmentData.params
  const slug = params.slug
}
```

```js filename="app/api/route.js" switcher
// Before
export async function GET(request, segmentData) {
  const params = segmentData.params
  const slug = params.slug
}
// After
export async function GET(request, segmentData) {
  const params = await segmentData.params
  const slug = params.slug
}
```

<AppOnly>

## `runtime` configuration (Breaking change)

The `runtime` [segment configuration](/docs/app/api-reference/file-conventions/route-segment-config#runtime) previously supported a value of `experimental-edge` in addition to `edge`. Both configurations refer to the same thing, and to simplify the options, we will now error if `experimental-edge` is used. To fix this, update your `runtime` configuration to `edge`. A [codemod](/docs/app/guides/upgrading/codemods#app-dir-runtime-config-experimental-edge) is available to automatically do this.

</AppOnly>

## `fetch` requests

[`fetch` requests](/docs/app/api-reference/functions/fetch) are no longer cached by default.

To opt specific `fetch` requests into caching, you can pass the `cache: 'force-cache'` option.

```js filename="app/layout.js"
export default async function RootLayout() {
  const a = await fetch('https://...') // Not Cached
  const b = await fetch('https://...', { cache: 'force-cache' }) // Cached
  // ...
}
```

To opt all `fetch` requests in a layout or page into caching, you can use the `export const fetchCache = 'default-cache'` [segment config option](/docs/app/api-reference/file-conventions/route-segment-config). If individual `fetch` requests specify a `cache` option, that will be used instead.

```js filename="app/layout.js"
// Since this is the root layout, all fetch requests in the app
// that don't set their own cache option will be cached.
export const fetchCache = 'default-cache'
export default async function RootLayout() {
  const a = await fetch('https://...') // Cached
  const b = await fetch('https://...', { cache: 'no-store' }) // Not cached
  // ...
}
```

## Route Handlers

`GET` functions in [Route Handlers](/docs/app/api-reference/file-conventions/route) are no longer cached by default. To opt `GET` methods into caching, you can use a [route config option](/docs/app/api-reference/file-conventions/route-segment-config) such as `export const dynamic = 'force-static'` in your Route Handler file.

```js filename="app/api/route.js"
export const dynamic = 'force-static'
export async function GET() {}
```

## Client-side Router Cache

When navigating between pages via `<Link>` or `useRouter`, [page](/docs/app/api-reference/file-conventions/page) segments are no longer reused from the client-side router cache. However, they are still reused during browser backward and forward navigation and for shared layouts.

To opt page segments into caching, you can use the [`staleTimes`](/docs/app/api-reference/config/next-config-js/staleTimes) config option:

```js filename="next.config.js"
/** @type {import('next').NextConfig} */
const nextConfig = {
  experimental: {
    staleTimes: {
      dynamic: 30,
      static: 180,
    },
  },
}
module.exports = nextConfig
```

[Layouts](/docs/app/api-reference/file-conventions/layout) and [loading states](/docs/app/api-reference/file-conventions/loading) are still cached and reused on navigation.

## `next/font`

The `@next/font` package has been removed in favor of the built-in [`next/font`](/docs/app/api-reference/components/font). A [codemod is available](/docs/app/guides/upgrading/codemods#built-in-next-font) to safely and automatically rename your imports.

```js filename="app/layout.js"
// Before
import { Inter } from '@next/font/google'
// After
import { Inter } from 'next/font/google'
```

## bundlePagesRouterDependencies

`experimental.bundlePagesExternals` is now stable and renamed to `bundlePagesRouterDependencies`.

```js filename="next.config.js"
/** @type {import('next').NextConfig} */
const nextConfig = {
  // Before
  experimental: {
    bundlePagesExternals: true,
  },
  // After
  bundlePagesRouterDependencies: true,
}
module.exports = nextConfig
```

## serverExternalPackages

`experimental.serverComponentsExternalPackages` is now stable and renamed to `serverExternalPackages`.

```js filename="next.config.js"
/** @type {import('next').NextConfig} */
const nextConfig = {
  // Before
  experimental: {
    serverComponentsExternalPackages: ['package-name'],
  },
  // After
  serverExternalPackages: ['package-name'],
}
module.exports = nextConfig
```

## Speed Insights

Auto instrumentation for Speed Insights was removed in Next.js 15.

To continue using Speed Insights, follow the [Vercel Speed Insights Quickstart](https://vercel.com/docs/speed-insights/quickstart) guide.

## `NextRequest` Geolocation

The `geo` and `ip` properties on `NextRequest` have been removed as these values are provided by your hosting provider. A [codemod](/docs/app/guides/upgrading/codemods#150) is available to automate this migration.

If you are using Vercel, you can alternatively use the `geolocation` and `ipAddress` functions from [`@vercel/functions`](https://vercel.com/docs/functions/vercel-functions-package) instead:

```ts filename="middleware.ts"
import { geolocation } from '@vercel/functions'
import type { NextRequest } from 'next/server'
export function middleware(request: NextRequest) {
  const { city } = geolocation(request)
  // ...
}
```

```ts filename="middleware.ts"
import { ipAddress } from '@vercel/functions'
import type { NextRequest } from 'next/server'
export function middleware(request: NextRequest) {
  const ip = ipAddress(request)
  // ...
}
```

	---
	title: How to upgrade to version 15
	nav_title: Version 15
	description: Upgrade your Next.js Application from Version 14 to 15.
	---

	{/* 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. */}

	## Upgrading from 14 to 15

	To update to Next.js version 15, you can use the `upgrade` codemod:

	```bash filename="Terminal"
	npx @next/codemod@canary upgrade latest
	```

	If you prefer to do it manually, ensure that you're installing the latest Next & React versions:

	```bash filename="Terminal"
	npm i next@latest react@latest react-dom@latest eslint-config-next@latest
	```

	> Good to know:
	>
	> - If you see a peer dependencies warning, you may need to update `react` and `react-dom` to the suggested versions, or use the `--force` or `--legacy-peer-deps` flag to ignore the warning. This won't be necessary once both Next.js 15 and React 19 are stable.

	## React 19

	- The minimum versions of `react` and `react-dom` is now 19.
	- `useFormState` has been replaced by `useActionState`. The `useFormState` hook is still available in React 19, but it is deprecated and will be removed in a future release. `useActionState` is recommended and includes additional properties like reading the `pending` state directly. [Learn more](https://react.dev/reference/react/useActionState).
	- `useFormStatus` now includes additional keys like `data`, `method`, and `action`. If you are not using React 19, only the `pending` key is available. [Learn more](https://react.dev/reference/react-dom/hooks/useFormStatus).
	- Read more in the [React 19 upgrade guide](https://react.dev/blog/2024/04/25/react-19-upgrade-guide).

	> Good to know: If you are using TypeScript, ensure you also upgrade `@types/react` and `@types/react-dom` to their latest versions.

	## Async Request APIs (Breaking change)

	Previously synchronous Dynamic APIs that rely on runtime information are now asynchronous:

	- [`cookies`](/docs/app/api-reference/functions/cookies)
	- [`headers`](/docs/app/api-reference/functions/headers)
	- [`draftMode`](/docs/app/api-reference/functions/draft-mode)
	- `params` in [`layout.js`](/docs/app/api-reference/file-conventions/layout), [`page.js`](/docs/app/api-reference/file-conventions/page), [`route.js`](/docs/app/api-reference/file-conventions/route), [`default.js`](/docs/app/api-reference/file-conventions/default), [`opengraph-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image), [`twitter-image`](/docs/app/api-reference/file-conventions/metadata/opengraph-image), [`icon`](/docs/app/api-reference/file-conventions/metadata/app-icons), and [`apple-icon`](/docs/app/api-reference/file-conventions/metadata/app-icons).
	- `searchParams` in [`page.js`](/docs/app/api-reference/file-conventions/page)

	To ease the burden of migration, a [codemod is available](/docs/app/guides/upgrading/codemods#150) to automate the process and the APIs can temporarily be accessed synchronously.

	### `cookies`

	#### Recommended Async Usage

	```tsx
	import { cookies } from 'next/headers'

	// Before
	const cookieStore = cookies()
	const token = cookieStore.get('token')

	// After
	const cookieStore = await cookies()
	const token = cookieStore.get('token')
	```

	#### Temporary Synchronous Usage

	```tsx filename="app/page.tsx" switcher
	import { cookies, type UnsafeUnwrappedCookies } from 'next/headers'

	// Before
	const cookieStore = cookies()
	const token = cookieStore.get('token')

	// After
	const cookieStore = cookies() as unknown as UnsafeUnwrappedCookies
	// will log a warning in dev
	const token = cookieStore.get('token')
	```

	```jsx filename="app/page.js" switcher
	import { cookies } from 'next/headers'

	// Before
	const cookieStore = cookies()
	const token = cookieStore.get('token')

	// After
	const cookieStore = cookies()
	// will log a warning in dev
	const token = cookieStore.get('token')
	```

	### `headers`

	#### Recommended Async Usage

	```tsx
	import { headers } from 'next/headers'

	// Before
	const headersList = headers()
	const userAgent = headersList.get('user-agent')

	// After
	const headersList = await headers()
	const userAgent = headersList.get('user-agent')
	```

	#### Temporary Synchronous Usage

	```tsx filename="app/page.tsx" switcher
	import { headers, type UnsafeUnwrappedHeaders } from 'next/headers'

	// Before
	const headersList = headers()
	const userAgent = headersList.get('user-agent')

	// After
	const headersList = headers() as unknown as UnsafeUnwrappedHeaders
	// will log a warning in dev
	const userAgent = headersList.get('user-agent')
	```

	```jsx filename="app/page.js" switcher
	import { headers } from 'next/headers'

	// Before
	const headersList = headers()
	const userAgent = headersList.get('user-agent')

	// After
	const headersList = headers()
	// will log a warning in dev
	const userAgent = headersList.get('user-agent')
	```

	### `draftMode`

	#### Recommended Async Usage

	```tsx
	import { draftMode } from 'next/headers'

	// Before
	const { isEnabled } = draftMode()

	// After
	const { isEnabled } = await draftMode()
	```

	#### Temporary Synchronous Usage

	```tsx filename="app/page.tsx" switcher
	import { draftMode, type UnsafeUnwrappedDraftMode } from 'next/headers'

	// Before
	const { isEnabled } = draftMode()

	// After
	// will log a warning in dev
	const { isEnabled } = draftMode() as unknown as UnsafeUnwrappedDraftMode
	```

	```jsx filename="app/page.js" switcher
	import { draftMode } from 'next/headers'

	// Before
	const { isEnabled } = draftMode()

	// After
	// will log a warning in dev
	const { isEnabled } = draftMode()
	```

	### `params` & `searchParams`

	#### Asynchronous Layout

	```tsx filename="app/layout.tsx" switcher
	// Before
	type Params = { slug: string }

	export function generateMetadata({ params }: { params: Params }) {
	const { slug } = params
	}

	export default async function Layout({
	children,
	params,
	}: {
	children: React.ReactNode
	params: Params
	}) {
	const { slug } = params
	}

	// After
	type Params = Promise<{ slug: string }>

	export async function generateMetadata({ params }: { params: Params }) {
	const { slug } = await params
	}

	export default async function Layout({
	children,
	params,
	}: {
	children: React.ReactNode
	params: Params
	}) {
	const { slug } = await params
	}
	```

	```jsx filename="app/layout.js" switcher
	// Before
	export function generateMetadata({ params }) {
	const { slug } = params
	}

	export default async function Layout({ children, params }) {
	const { slug } = params
	}

	// After
	export async function generateMetadata({ params }) {
	const { slug } = await params
	}

	export default async function Layout({ children, params }) {
	const { slug } = await params
	}
	```

	#### Synchronous Layout

	```tsx filename="app/layout.tsx" switcher
	// Before
	type Params = { slug: string }

	export default function Layout({
	children,
	params,
	}: {
	children: React.ReactNode
	params: Params
	}) {
	const { slug } = params
	}

	// After
	import { use } from 'react'

	type Params = Promise<{ slug: string }>

	export default function Layout(props: {
	children: React.ReactNode
	params: Params
	}) {
	const params = use(props.params)
	const slug = params.slug
	}
	```

	```jsx filename="app/layout.js" switcher
	// Before
	export default function Layout({ children, params }) {
	const { slug } = params
	}

	// After
	import { use } from 'react'
	export default async function Layout(props) {
	const params = use(props.params)
	const slug = params.slug
	}

	```

	#### Asynchronous Page

	```tsx filename="app/page.tsx" switcher
	// Before
	type Params = { slug: string }
	type SearchParams = { [key: string]: string \| string[] \| undefined }

	export function generateMetadata({
	params,
	searchParams,
	}: {
	params: Params
	searchParams: SearchParams
	}) {
	const { slug } = params
	const { query } = searchParams
	}

	export default async function Page({
	params,
	searchParams,
	}: {
	params: Params
	searchParams: SearchParams
	}) {
	const { slug } = params
	const { query } = searchParams
	}

	// After
	type Params = Promise<{ slug: string }>
	type SearchParams = Promise<{ [key: string]: string \| string[] \| undefined }>

	export async function generateMetadata(props: {
	params: Params
	searchParams: SearchParams
	}) {
	const params = await props.params
	const searchParams = await props.searchParams
	const slug = params.slug
	const query = searchParams.query
	}

	export default async function Page(props: {
	params: Params
	searchParams: SearchParams
	}) {
	const params = await props.params
	const searchParams = await props.searchParams
	const slug = params.slug
	const query = searchParams.query
	}
	```

	```jsx filename="app/page.js" switcher
	// Before
	export function generateMetadata({ params, searchParams }) {
	const { slug } = params
	const { query } = searchParams
	}

	export default function Page({ params, searchParams }) {
	const { slug } = params
	const { query } = searchParams
	}

	// After
	export async function generateMetadata(props) {
	const params = await props.params
	const searchParams = await props.searchParams
	const slug = params.slug
	const query = searchParams.query
	}

	export async function Page(props) {
	const params = await props.params
	const searchParams = await props.searchParams
	const slug = params.slug
	const query = searchParams.query
	}
	```

	#### Synchronous Page

	```tsx
	'use client'

	// Before
	type Params = { slug: string }
	type SearchParams = { [key: string]: string \| string[] \| undefined }

	export default function Page({
	params,
	searchParams,
	}: {
	params: Params
	searchParams: SearchParams
	}) {
	const { slug } = params
	const { query } = searchParams
	}

	// After
	import { use } from 'react'

	type Params = Promise<{ slug: string }>
	type SearchParams = Promise<{ [key: string]: string \| string[] \| undefined }>

	export default function Page(props: {
	params: Params
	searchParams: SearchParams
	}) {
	const params = use(props.params)
	const searchParams = use(props.searchParams)
	const slug = params.slug
	const query = searchParams.query
	}
	```

	```jsx
	// Before
	export default function Page({ params, searchParams }) {
	const { slug } = params
	const { query } = searchParams
	}

	// After
	import { use } from "react"

	export default function Page(props) {
	const params = use(props.params)
	const searchParams = use(props.searchParams)
	const slug = params.slug
	const query = searchParams.query
	}

	```

	#### Route Handlers

	```tsx filename="app/api/route.ts" switcher
	// Before
	type Params = { slug: string }

	export async function GET(request: Request, segmentData: { params: Params }) {
	const params = segmentData.params
	const slug = params.slug
	}

	// After
	type Params = Promise<{ slug: string }>

	export async function GET(request: Request, segmentData: { params: Params }) {
	const params = await segmentData.params
	const slug = params.slug
	}
	```

	```js filename="app/api/route.js" switcher
	// Before
	export async function GET(request, segmentData) {
	const params = segmentData.params
	const slug = params.slug
	}

	// After
	export async function GET(request, segmentData) {
	const params = await segmentData.params
	const slug = params.slug
	}
	```

	<AppOnly>

	## `runtime` configuration (Breaking change)

	The `runtime` [segment configuration](/docs/app/api-reference/file-conventions/route-segment-config#runtime) previously supported a value of `experimental-edge` in addition to `edge`. Both configurations refer to the same thing, and to simplify the options, we will now error if `experimental-edge` is used. To fix this, update your `runtime` configuration to `edge`. A [codemod](/docs/app/guides/upgrading/codemods#app-dir-runtime-config-experimental-edge) is available to automatically do this.

	</AppOnly>

	## `fetch` requests

	[`fetch` requests](/docs/app/api-reference/functions/fetch) are no longer cached by default.

	To opt specific `fetch` requests into caching, you can pass the `cache: 'force-cache'` option.

	```js filename="app/layout.js"
	export default async function RootLayout() {
	const a = await fetch('https://...') // Not Cached
	const b = await fetch('https://...', { cache: 'force-cache' }) // Cached

	// ...
	}
	```

	To opt all `fetch` requests in a layout or page into caching, you can use the `export const fetchCache = 'default-cache'` [segment config option](/docs/app/api-reference/file-conventions/route-segment-config). If individual `fetch` requests specify a `cache` option, that will be used instead.

	```js filename="app/layout.js"
	// Since this is the root layout, all fetch requests in the app
	// that don't set their own cache option will be cached.
	export const fetchCache = 'default-cache'

	export default async function RootLayout() {
	const a = await fetch('https://...') // Cached
	const b = await fetch('https://...', { cache: 'no-store' }) // Not cached

	// ...
	}
	```

	## Route Handlers

	`GET` functions in [Route Handlers](/docs/app/api-reference/file-conventions/route) are no longer cached by default. To opt `GET` methods into caching, you can use a [route config option](/docs/app/api-reference/file-conventions/route-segment-config) such as `export const dynamic = 'force-static'` in your Route Handler file.

	```js filename="app/api/route.js"
	export const dynamic = 'force-static'

	export async function GET() {}
	```

	## Client-side Router Cache

	When navigating between pages via `<Link>` or `useRouter`, [page](/docs/app/api-reference/file-conventions/page) segments are no longer reused from the client-side router cache. However, they are still reused during browser backward and forward navigation and for shared layouts.

	To opt page segments into caching, you can use the [`staleTimes`](/docs/app/api-reference/config/next-config-js/staleTimes) config option:

	```js filename="next.config.js"
	/** @type {import('next').NextConfig} */
	const nextConfig = {
	experimental: {
	staleTimes: {
	dynamic: 30,
	static: 180,
	},
	},
	}

	module.exports = nextConfig
	```

	[Layouts](/docs/app/api-reference/file-conventions/layout) and [loading states](/docs/app/api-reference/file-conventions/loading) are still cached and reused on navigation.

	## `next/font`

	The `@next/font` package has been removed in favor of the built-in [`next/font`](/docs/app/api-reference/components/font). A [codemod is available](/docs/app/guides/upgrading/codemods#built-in-next-font) to safely and automatically rename your imports.

	```js filename="app/layout.js"
	// Before
	import { Inter } from '@next/font/google'

	// After
	import { Inter } from 'next/font/google'
	```

	## bundlePagesRouterDependencies

	`experimental.bundlePagesExternals` is now stable and renamed to `bundlePagesRouterDependencies`.

	```js filename="next.config.js"
	/** @type {import('next').NextConfig} */
	const nextConfig = {
	// Before
	experimental: {
	bundlePagesExternals: true,
	},

	// After
	bundlePagesRouterDependencies: true,
	}

	module.exports = nextConfig
	```

	## serverExternalPackages

	`experimental.serverComponentsExternalPackages` is now stable and renamed to `serverExternalPackages`.

	```js filename="next.config.js"
	/** @type {import('next').NextConfig} */
	const nextConfig = {
	// Before
	experimental: {
	serverComponentsExternalPackages: ['package-name'],
	},

	// After
	serverExternalPackages: ['package-name'],
	}

	module.exports = nextConfig
	```

	## Speed Insights

	Auto instrumentation for Speed Insights was removed in Next.js 15.

	To continue using Speed Insights, follow the [Vercel Speed Insights Quickstart](https://vercel.com/docs/speed-insights/quickstart) guide.

	## `NextRequest` Geolocation

	The `geo` and `ip` properties on `NextRequest` have been removed as these values are provided by your hosting provider. A [codemod](/docs/app/guides/upgrading/codemods#150) is available to automate this migration.

	If you are using Vercel, you can alternatively use the `geolocation` and `ipAddress` functions from [`@vercel/functions`](https://vercel.com/docs/functions/vercel-functions-package) instead:

	```ts filename="middleware.ts"
	import { geolocation } from '@vercel/functions'
	import type { NextRequest } from 'next/server'

	export function middleware(request: NextRequest) {
	const { city } = geolocation(request)

	// ...
	}
	```

	```ts filename="middleware.ts"
	import { ipAddress } from '@vercel/functions'
	import type { NextRequest } from 'next/server'

	export function middleware(request: NextRequest) {
	const ip = ipAddress(request)

	// ...
	}
	```