---
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=" output" hideLineNumbers
```
**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=" output" hideLineNumbers
```
### `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=" output" hideLineNumbers
```
### `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=" output" hideLineNumbers
```
## 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
/** @type {import("next").Viewport} */
export const viewport = {
themeColor: 'black',
}
```
## Version History
| Version | Changes |
| --------- | --------------------------------------------- |
| `v14.0.0` | `viewport` and `generateViewport` introduced. |