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Host header

files/en-us/web/http/reference/headers/host/index.md

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The HTTP Host {{Glossary("request header")}} specifies the host and port number of the server to which the request is being sent.

If no port is included, the default port for the service requested is implied (e.g., 443 for an HTTPS URL, and 80 for an HTTP URL).

A Host header field must be sent in all HTTP/1.1 request messages. A {{HTTPStatus("400", "400 Bad Request")}} status code may be sent to any HTTP/1.1 request message that lacks or contains more than one Host header field.

<table class="properties"> <tbody> <tr> <th scope="row">Header type</th> <td>{{Glossary("Request header")}}</td> </tr> <tr> <th scope="row">{{Glossary("Forbidden request header")}}</th> <td>Yes</td> </tr> </tbody> </table>

Syntax

http
Host: <host>:<port>

Directives

  • <host>
    • : The domain name of the server (for virtual hosting).
  • <port> {{optional_inline}}
    • : TCP port number on which the server is listening.

Examples

http
Host: developer.mozilla.org

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

  • {{HTTPStatus("400")}}
  • {{HTMLElement("base")}}