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--- |
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title: generateViewport |
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description: API Reference for the generateViewport function. |
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related: |
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title: Next Steps |
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description: View all the Metadata API options. |
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links: |
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- app/api-reference/file-conventions/metadata |
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--- |
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You can customize the initial viewport of the page with the static `viewport` object or the dynamic `generateViewport` function. |
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> **Good to know**: |
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> |
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> - The `viewport` object and `generateViewport` function exports are **only supported in Server Components**. |
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> - You cannot export both the `viewport` object and `generateViewport` function from the same route segment. |
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> - If you're coming from migrating `metadata` exports, you can use [metadata-to-viewport-export codemod](/docs/app/guides/upgrading/codemods#metadata-to-viewport-export) to update your changes. |
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## The `viewport` object |
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To define the viewport options, export a `viewport` object from a `layout.jsx` or `page.jsx` file. |
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```tsx filename="layout.tsx | page.tsx" switcher |
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import type { Viewport } from 'next' |
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export const viewport: Viewport = { |
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themeColor: 'black', |
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} |
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export default function Page() {} |
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``` |
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```jsx filename="layout.jsx | page.jsx" switcher |
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export const viewport = { |
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themeColor: 'black', |
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} |
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export default function Page() {} |
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``` |
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## `generateViewport` function |
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`generateViewport` should return a [`Viewport` object](#viewport-fields) containing one or more viewport fields. |
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```tsx filename="layout.tsx | page.tsx" switcher |
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export function generateViewport({ params }) { |
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return { |
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themeColor: '...', |
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} |
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} |
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``` |
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```jsx filename="layout.js | page.js" switcher |
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export function generateViewport({ params }) { |
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return { |
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themeColor: '...', |
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} |
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} |
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``` |
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> **Good to know**: |
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> |
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> - If the viewport doesn't depend on runtime information, it should be defined using the static [`viewport` object](#the-viewport-object) rather than `generateViewport`. |
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## Viewport Fields |
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### `themeColor` |
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Learn more about [`theme-color`](https://developer.mozilla.org/docs/Web/HTML/Element/meta/name/theme-color). |
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**Simple theme color** |
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```tsx filename="layout.tsx | page.tsx" switcher |
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import type { Viewport } from 'next' |
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export const viewport: Viewport = { |
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themeColor: 'black', |
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} |
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``` |
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```jsx filename="layout.jsx | page.jsx" switcher |
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export const viewport = { |
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themeColor: 'black', |
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} |
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``` |
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```html filename="<head> output" hideLineNumbers |
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<meta name="theme-color" content="black" /> |
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``` |
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**With media attribute** |
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```tsx filename="layout.tsx | page.tsx" switcher |
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import type { Viewport } from 'next' |
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export const viewport: Viewport = { |
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themeColor: [ |
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{ media: '(prefers-color-scheme: light)', color: 'cyan' }, |
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{ media: '(prefers-color-scheme: dark)', color: 'black' }, |
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], |
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} |
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``` |
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```jsx filename="layout.jsx | page.jsx" switcher |
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export const viewport = { |
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themeColor: [ |
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{ media: '(prefers-color-scheme: light)', color: 'cyan' }, |
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{ media: '(prefers-color-scheme: dark)', color: 'black' }, |
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], |
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} |
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``` |
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```html filename="<head> output" hideLineNumbers |
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<meta name="theme-color" media="(prefers-color-scheme: light)" content="cyan" /> |
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<meta name="theme-color" media="(prefers-color-scheme: dark)" content="black" /> |
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``` |
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### `width`, `initialScale`, `maximumScale` and `userScalable` |
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> **Good to know**: The `viewport` meta tag is automatically set, and manual configuration is usually unnecessary as the default is sufficient. However, the information is provided for completeness. |
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```tsx filename="layout.tsx | page.tsx" switcher |
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import type { Viewport } from 'next' |
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export const viewport: Viewport = { |
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width: 'device-width', |
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initialScale: 1, |
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maximumScale: 1, |
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userScalable: false, |
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// Also supported but less commonly used |
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// interactiveWidget: 'resizes-visual', |
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} |
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``` |
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```jsx filename="layout.jsx | page.jsx" switcher |
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export const viewport = { |
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width: 'device-width', |
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initialScale: 1, |
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maximumScale: 1, |
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userScalable: false, |
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// Also supported but less commonly used |
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// interactiveWidget: 'resizes-visual', |
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} |
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``` |
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```html filename="<head> output" hideLineNumbers |
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<meta |
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name="viewport" |
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content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no" |
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/> |
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``` |
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### `colorScheme` |
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Learn more about [`color-scheme`](https://developer.mozilla.org/en-US/docs/Web/HTML/Element/meta/name#:~:text=color%2Dscheme%3A%20specifies,of%20the%20following%3A). |
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```tsx filename="layout.tsx | page.tsx" switcher |
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import type { Viewport } from 'next' |
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export const viewport: Viewport = { |
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colorScheme: 'dark', |
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} |
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``` |
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```jsx filename="layout.jsx | page.jsx" switcher |
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export const viewport = { |
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colorScheme: 'dark', |
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} |
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``` |
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```html filename="<head> output" hideLineNumbers |
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<meta name="color-scheme" content="dark" /> |
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``` |
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## Types |
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You can add type safety to your viewport object by using the `Viewport` type. If you are using the [built-in TypeScript plugin](/docs/app/api-reference/config/typescript) in your IDE, you do not need to manually add the type, but you can still explicitly add it if you want. |
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### `viewport` object |
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```tsx |
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import type { Viewport } from 'next' |
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export const viewport: Viewport = { |
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themeColor: 'black', |
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} |
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``` |
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### `generateViewport` function |
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#### Regular function |
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```tsx |
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import type { Viewport } from 'next' |
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export function generateViewport(): Viewport { |
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return { |
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themeColor: 'black', |
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} |
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} |
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``` |
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#### With segment props |
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```tsx |
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import type { Viewport } from 'next' |
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type Props = { |
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params: Promise<{ id: string }> |
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searchParams: Promise<{ [key: string]: string | string[] | undefined }> |
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} |
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export function generateViewport({ params, searchParams }: Props): Viewport { |
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return { |
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themeColor: 'black', |
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} |
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} |
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export default function Page({ params, searchParams }: Props) {} |
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``` |
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#### JavaScript Projects |
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For JavaScript projects, you can use JSDoc to add type safety. |
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```js |
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export const viewport = { |
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themeColor: 'black', |
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} |
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``` |
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## Version History |
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| Version | Changes | |
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| --------- | --------------------------------------------- | |
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| `v14.0.0` | `viewport` and `generateViewport` introduced. | |
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