| --- |
| title: headers |
| description: API reference for the headers function. |
| --- |
|
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| `headers` is an **async** function that allows you to **read** the HTTP incoming request headers from a [Server Component](/docs/app/getting-started/server-and-client-components). |
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| ```tsx filename="app/page.tsx" switcher |
| import { headers } from 'next/headers' |
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| export default async function Page() { |
| const headersList = await headers() |
| const userAgent = headersList.get('user-agent') |
| } |
| ``` |
|
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| ```jsx filename="app/page.js" switcher |
| import { headers } from 'next/headers' |
|
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| export default async function Page() { |
| const headersList = await headers() |
| const userAgent = headersList.get('user-agent') |
| } |
| ``` |
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| `headers` does not take any parameters. |
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| `headers` returns a **read-only** [Web Headers](https://developer.mozilla.org/docs/Web/API/Headers) object. |
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| - [`Headers.entries()`](https://developer.mozilla.org/docs/Web/API/Headers/entries): Returns an [`iterator`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Iteration_protocols) allowing to go through all key/value pairs contained in this object. |
| - [`Headers.forEach()`](https://developer.mozilla.org/docs/Web/API/Headers/forEach): Executes a provided function once for each key/value pair in this `Headers` object. |
| - [`Headers.get()`](https://developer.mozilla.org/docs/Web/API/Headers/get): Returns a [`String`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String) sequence of all the values of a header within a `Headers` object with a given name. |
| - [`Headers.has()`](https://developer.mozilla.org/docs/Web/API/Headers/has): Returns a boolean stating whether a `Headers` object contains a certain header. |
| - [`Headers.keys()`](https://developer.mozilla.org/docs/Web/API/Headers/keys): Returns an [`iterator`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Iteration_protocols) allowing you to go through all keys of the key/value pairs contained in this object. |
| - [`Headers.values()`](https://developer.mozilla.org/docs/Web/API/Headers/values): Returns an [`iterator`](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Iteration_protocols) allowing you to go through all values of the key/value pairs contained in this object. |
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| - `headers` is an **asynchronous** function that returns a promise. You must use `async/await` or React's [`use`](https://react.dev/reference/react/use) function. |
| - In version 14 and earlier, `headers` was a synchronous function. To help with backwards compatibility, you can still access it synchronously in Next.js 15, but this behavior will be deprecated in the future. |
| - Since `headers` is read-only, you cannot `set` or `delete` the outgoing request headers. |
| - `headers` is a [Dynamic API](/docs/app/getting-started/partial-prerendering |
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| ```jsx filename="app/page.js" |
| import { headers } from 'next/headers' |
|
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| export default async function Page() { |
| const authorization = (await headers()).get('authorization') |
| const res = await fetch('...', { |
| headers: { authorization }, // Forward the authorization header |
| }) |
| const user = await res.json() |
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| return <h1>{user.name}</h1> |
| } |
| ``` |
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| | Version | Changes | |
| | ------------ | ------------------------------------------------------------------------------------------------------ | |
| | `v15.0.0-RC` | `headers` is now an async function. A [codemod](/docs/app/guides/upgrading/codemods |
| | `v13.0.0` | `headers` introduced. | |
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