The Host 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 (e.g., 443 for an HTTPS URL, and 80 for an HTTP URL) is implied.

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

Header type Request header
Forbidden header name yes


Host: <host>:<port>


the domain name of the server (for virtual hosting).
<port> Optional
TCP port number on which the server is listening.




Specification Title
RFC 7230, section 5.4: Host Hypertext Transfer Protocol (HTTP/1.1): Message Syntax and Routing

Browser compatibility

BCD tables only load in the browser

See also