# HttpRequestHeader()

Retrieves the header from an HTTP request for a landing page. You can only use this function to retrieve the standard HTTP headers outlined in RFC 7231.

## Availability

<table>
  <tr>
    <td>Marketing Cloud Engagement</td>
    <td>✅ Yes</td>
  </tr>
  <tr>
    <td>Marketing Cloud Next</td>
    <td>❌ No</td>
  </tr>
</table>

## Syntax

```
HttpRequestHeader(headerToRetrieve)
```

The `HttpRequestHeader(headerToRetrieve)` function has one parameter:

- `headerToRetrieve` (string): Required. The header that you want to retrieve.

## Function Properties

To use this function, pass it the name of the header that you want to retrieve.

```
%%=HTTPRequestHeader('User-Agent')=%%
```

The function returns the value of the User-Agent header for the HTTP request.

## See Also

- [RFC 7231](https://datatracker.ietf.org/doc/html/rfc7231) on IETF.org