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

# Modifying HTTP headers using .htaccess files

> You can use .htaccess directives to modify the HTTP headers Apache sends to a Client. Learn how here.

This article demonstrates how to directly modify the HTTP headers that Apache sends to a client.

## Modifying HTTP headers

The Apache configuration on hosting.com servers includes the **mod\_headers** module. This means that you can easily add, modify, and delete HTTP response headers by using the **Header** directive in an *.htaccess* file.

<Tip>
  A browser plugin that enables you to view the raw headers (such as Live HTTP headers for Firefox) makes troubleshooting much easier when working with headers. These types of plugins allow you to see the raw request and response HTTP headers as they are sent and received.
</Tip>

### Adding a header

To add a custom header to the HTTP response headers, use the **set** or **append** option. The **set** option sets the specified header and replaces any header that has the same name. Alternatively, the **append** option sets the header if it does not already exist. If the header already exists, however, the **append** option adds to the existing header value.

For example, the following sample configuration demonstrates how to set a header and append to a header:

```
<IfModule mod_headers.c>
  Header set Animal cow
  Header set Animal monkey
  Header append Animal camel
</IfModule>
```

In this example, the **Animal** header is first set to *cow*. But because the next header option is also **set**, the **Animal** header is reset to *monkey*. Lastly, *camel* is appended to the **Animal** header. This generates an HTTP response header that resembles the following:

```
HTTP/1.1 200 OK
Date: Tue, 24 Jun 2014 15:23:33 GMT
Server: Apache
Animal: monkey, camel
```

### Editing a header

To edit a header, use the **edit** option. With the **edit** option, you can use regular expressions to do search-and-replace operations on header values.

For example, the following sample configuration demonstrates how to do a simple search-and-replace operation on a header:

```
<IfModule mod_headers.c>
  Header set Animal monkey 
  Header append Animal camel
  Header edit Animal "camel" "llama"
</IfModule>
```

In this example, *camel* is replaced by *llama*. This generates an HTTP response header that resembles the following:

```
HTTP/1.1 200 OK
Date: Tue, 24 Jun 2014 15:42:21 GMT
Server: Apache
Animal: monkey, llama
```

<Note>
  The **Header edit** option runs *before* any application-generated headers. Therefore, if you are trying to modify a header that is generated by an application (for example, WordPress or Drupal), you should use the **Header always edit** option instead. This option ensures that Apache modifies the headers *after* an application generates them.
</Note>

### Removing a header

To completely remove a header from an HTTP response, use the **unset** option.

The following sample configuration demonstrates how to remove a header:

```
<IfModule mod_headers.c>
  Header unset Animal
</IfModule>
```

## More information

For more information about the Apache **mod\_headers** module and the **Header** directive, please visit [https://httpd.apache.org/docs/2.2/mod/mod\_headers.html](https://httpd.apache.org/docs/2.2/mod/mod_headers.html).

## Related articles

* [Using .htaccess files](/docs/using-htaccess-files)