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.
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
http
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
http
Host: developer.mozilla.org
Specifications
| Specification |
|---|
| HTTP Semantics # field.host |
Browser compatibility
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Legend
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- Full support
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