| --- |
| title: generateViewport |
| description: API Reference for the generateViewport function. |
| related: |
| title: Next Steps |
| description: View all the Metadata API options. |
| links: |
| - app/api-reference/file-conventions/metadata |
| --- |
|
|
| You can customize the initial viewport of the page with the static `viewport` object or the dynamic `generateViewport` function. |
|
|
| > **Good to know**: |
| > |
| > - The `viewport` object and `generateViewport` function exports are **only supported in Server Components**. |
| > - You cannot export both the `viewport` object and `generateViewport` function from the same route segment. |
| > - 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. |
|
|
| ## The `viewport` object |
|
|
| To define the viewport options, export a `viewport` object from a `layout.jsx` or `page.jsx` file. |
|
|
| ```tsx filename="layout.tsx | page.tsx" switcher |
| import type { Viewport } from 'next' |
|
|
| export const viewport: Viewport = { |
| themeColor: 'black', |
| } |
|
|
| export default function Page() {} |
| ``` |
|
|
| ```jsx filename="layout.jsx | page.jsx" switcher |
| export const viewport = { |
| themeColor: 'black', |
| } |
|
|
| export default function Page() {} |
| ``` |
|
|
| ## `generateViewport` function |
|
|
| `generateViewport` should return a [`Viewport` object](#viewport-fields) containing one or more viewport fields. |
|
|
| ```tsx filename="layout.tsx | page.tsx" switcher |
| export function generateViewport({ params }) { |
| return { |
| themeColor: '...', |
| } |
| } |
| ``` |
|
|
| ```jsx filename="layout.js | page.js" switcher |
| export function generateViewport({ params }) { |
| return { |
| themeColor: '...', |
| } |
| } |
| ``` |
|
|
| > **Good to know**: |
| > |
| > - If the viewport doesn't depend on runtime information, it should be defined using the static [`viewport` object](#the-viewport-object) rather than `generateViewport`. |
|
|
| ## Viewport Fields |
|
|
| ### `themeColor` |
|
|
| Learn more about [`theme-color`](https://developer.mozilla.org/docs/Web/HTML/Element/meta/name/theme-color). |
|
|
| **Simple theme color** |
|
|
| ```tsx filename="layout.tsx | page.tsx" switcher |
| import type { Viewport } from 'next' |
|
|
| export const viewport: Viewport = { |
| themeColor: 'black', |
| } |
| ``` |
|
|
| ```jsx filename="layout.jsx | page.jsx" switcher |
| export const viewport = { |
| themeColor: 'black', |
| } |
| ``` |
|
|
| ```html filename="<head> output" hideLineNumbers |
| <meta name="theme-color" content="black" /> |
| ``` |
|
|
| **With media attribute** |
|
|
| ```tsx filename="layout.tsx | page.tsx" switcher |
| import type { Viewport } from 'next' |
|
|
| export const viewport: Viewport = { |
| themeColor: [ |
| { media: '(prefers-color-scheme: light)', color: 'cyan' }, |
| { media: '(prefers-color-scheme: dark)', color: 'black' }, |
| ], |
| } |
| ``` |
|
|
| ```jsx filename="layout.jsx | page.jsx" switcher |
| export const viewport = { |
| themeColor: [ |
| { media: '(prefers-color-scheme: light)', color: 'cyan' }, |
| { media: '(prefers-color-scheme: dark)', color: 'black' }, |
| ], |
| } |
| ``` |
|
|
| ```html filename="<head> output" hideLineNumbers |
| <meta name="theme-color" media="(prefers-color-scheme: light)" content="cyan" /> |
| <meta name="theme-color" media="(prefers-color-scheme: dark)" content="black" /> |
| ``` |
|
|
| ### `width`, `initialScale`, `maximumScale` and `userScalable` |
|
|
| > **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. |
|
|
| ```tsx filename="layout.tsx | page.tsx" switcher |
| import type { Viewport } from 'next' |
|
|
| export const viewport: Viewport = { |
| width: 'device-width', |
| initialScale: 1, |
| maximumScale: 1, |
| userScalable: false, |
| // Also supported but less commonly used |
| // interactiveWidget: 'resizes-visual', |
| } |
| ``` |
|
|
| ```jsx filename="layout.jsx | page.jsx" switcher |
| export const viewport = { |
| width: 'device-width', |
| initialScale: 1, |
| maximumScale: 1, |
| userScalable: false, |
| // Also supported but less commonly used |
| // interactiveWidget: 'resizes-visual', |
| } |
| ``` |
|
|
| ```html filename="<head> output" hideLineNumbers |
| <meta |
| name="viewport" |
| content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no" |
| /> |
| ``` |
|
|
| ### `colorScheme` |
|
|
| 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). |
|
|
| ```tsx filename="layout.tsx | page.tsx" switcher |
| import type { Viewport } from 'next' |
|
|
| export const viewport: Viewport = { |
| colorScheme: 'dark', |
| } |
| ``` |
|
|
| ```jsx filename="layout.jsx | page.jsx" switcher |
| export const viewport = { |
| colorScheme: 'dark', |
| } |
| ``` |
|
|
| ```html filename="<head> output" hideLineNumbers |
| <meta name="color-scheme" content="dark" /> |
| ``` |
|
|
| ## Types |
|
|
| 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. |
|
|
| ### `viewport` object |
|
|
| ```tsx |
| import type { Viewport } from 'next' |
|
|
| export const viewport: Viewport = { |
| themeColor: 'black', |
| } |
| ``` |
|
|
| ### `generateViewport` function |
|
|
| #### Regular function |
|
|
| ```tsx |
| import type { Viewport } from 'next' |
|
|
| export function generateViewport(): Viewport { |
| return { |
| themeColor: 'black', |
| } |
| } |
| ``` |
|
|
| #### With segment props |
|
|
| ```tsx |
| import type { Viewport } from 'next' |
|
|
| type Props = { |
| params: Promise<{ id: string }> |
| searchParams: Promise<{ [key: string]: string | string[] | undefined }> |
| } |
|
|
| export function generateViewport({ params, searchParams }: Props): Viewport { |
| return { |
| themeColor: 'black', |
| } |
| } |
|
|
| export default function Page({ params, searchParams }: Props) {} |
| ``` |
|
|
| #### JavaScript Projects |
|
|
| For JavaScript projects, you can use JSDoc to add type safety. |
|
|
| ```js |
| |
| export const viewport = { |
| themeColor: 'black', |
| } |
| ``` |
|
|
| ## Version History |
|
|
| | Version | Changes | |
| | --------- | --------------------------------------------- | |
| | `v14.0.0` | `viewport` and `generateViewport` introduced. | |
|
|
