> ## Documentation Index
> Fetch the complete documentation index at: https://mintlify.com/vercel/next.js/llms.txt
> Use this file to discover all available pages before exploring further.

# headers

> API reference for the headers() function, used to read HTTP request headers in Server Components.

`headers` is an **async** function that lets you read the HTTP incoming request headers from a [Server Component](/app/getting-started/server-and-client-components).

```typescript app/page.tsx theme={null}
import { headers } from 'next/headers'

export default async function Page() {
  const headersList = await headers()
  const userAgent = headersList.get('user-agent')
}
```

## Parameters

`headers` takes no parameters.

## Returns

`headers` returns a **read-only** [Web `Headers`](https://developer.mozilla.org/docs/Web/API/Headers) object.

<ResponseField name="get(name)" type="string | null">
  Returns the string value of the named header, or `null` if not present.
</ResponseField>

<ResponseField name="has(name)" type="boolean">
  Returns `true` if the header exists.
</ResponseField>

<ResponseField name="keys()" type="IterableIterator<string>">
  Returns an iterator over all header names.
</ResponseField>

<ResponseField name="values()" type="IterableIterator<string>">
  Returns an iterator over all header values.
</ResponseField>

<ResponseField name="entries()" type="IterableIterator<[string, string]>">
  Returns an iterator over all `[name, value]` pairs.
</ResponseField>

<ResponseField name="forEach(callback)" type="void">
  Executes a callback for each key/value pair.
</ResponseField>

## Good to know

* `headers` is **async** and returns a promise. Use `async/await` or React's [`use`](https://react.dev/reference/react/use).
* In Next.js 14 and earlier, `headers` was synchronous. Synchronous access still works in Next.js 15 for backwards compatibility, but is deprecated.
* The returned `Headers` object is **read-only** — you cannot `set` or `delete` headers.
* `headers` is a [Request-time API](/app/core-concepts/routing#request-time-apis). Using it opts the route into [dynamic rendering](/app/core-concepts/routing#dynamic-rendering).

## Examples

### Forwarding the Authorization header

```typescript app/page.tsx theme={null}
import { headers } from 'next/headers'

export default async function Page() {
  const authorization = (await headers()).get('authorization')
  const res = await fetch('https://api.example.com/user', {
    headers: { authorization }, // forward the authorization header
  })
  const user = await res.json()

  return <h1>{user.name}</h1>
}
```

### Reading multiple headers

```typescript app/page.tsx theme={null}
import { headers } from 'next/headers'

export default async function Page() {
  const headersList = await headers()

  return (
    <ul>
      {[...headersList.entries()].map(([name, value]) => (
        <li key={name}>
          {name}: {value}
        </li>
      ))}
    </ul>
  )
}
```

## Version history

| Version      | Changes                                                                                                  |
| ------------ | -------------------------------------------------------------------------------------------------------- |
| `v15.0.0-RC` | `headers` is now async. A [codemod](https://nextjs.org/docs/app/guides/upgrading/codemods) is available. |
| `v13.0.0`    | `headers` introduced.                                                                                    |