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---
title: headers
description: API reference for the headers function.
---
`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).
```tsx filename="app/page.tsx" switcher
import { headers } from 'next/headers'
export default async function Page() {
const headersList = await headers()
const userAgent = headersList.get('user-agent')
}
```
```jsx filename="app/page.js" switcher
import { headers } from 'next/headers'
export default async function Page() {
const headersList = await headers()
const userAgent = headersList.get('user-agent')
}
```
## Reference
### Parameters
`headers` does not take any parameters.
### Returns
`headers` returns a **read-only** [Web Headers](https://developer.mozilla.org/docs/Web/API/Headers) object.
- [`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.
## Good to know
- `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#dynamic-rendering#dynamic-apis) whose returned values cannot be known ahead of time. Using it in will opt a route into **[dynamic rendering](/docs/app/getting-started/partial-prerendering#dynamic-rendering)**.
## Examples
### Using the Authorization header
```jsx filename="app/page.js"
import { headers } from 'next/headers'
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()
return <h1>{user.name}</h1>
}
```
## Version History
| Version | Changes |
| ------------ | ------------------------------------------------------------------------------------------------------ |
| `v15.0.0-RC` | `headers` is now an async function. A [codemod](/docs/app/guides/upgrading/codemods#150) is available. |
| `v13.0.0` | `headers` introduced. |
|