Headers: Host

Host header

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

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See full compatibility

The HTTP 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 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 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.

Header type	Request header
Forbidden request header	Yes

Syntax

Host: <host>:<port>

Directives

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

Examples

Host: developer.mozilla.org

Specifications

Specification
HTTP Semantics> # field.host>

Browser compatibility

	Desktop					Mobile
	Chrome	Edge	Firefox	Opera	Safari	Chrome Android	Firefox for Android	Opera Android	Safari on IOS	Samsung Internet	WebView Android	WebView on iOS
`Host`	1	12	1	15	1	18	4	14	1	1.0	4.4	1