HTTP location

The HTTP Location header field is returned in responses from an HTTP server under two circumstances:

An obsolete version of the HTTP 1.1 specifications (IETF RFC 2616) required a complete absolute URI for redirection. The IETF HTTP working group found that the most popular web browsers tolerate the passing of a relative URL and, consequently, the updated HTTP 1.1 specifications (IETF RFC 7231) relaxed the original constraint, allowing the use of relative URLs in Location headers.

Absolute URLs are URLs that start with a scheme (e.g., http:, https:, telnet:, mailto:) and conform to scheme-specific syntax and semantics. For example, the HTTP scheme-specific syntax and semantics for HTTP URLs requires a "host" (web server address) and "absolute path", with optional components of "port" and "query".

Client request:

Server response:

Relative URLs are URLs that do not include a scheme or a host. In order to be understood they must be combined with the URL of the original request.

Client request for http://www.example.com/blog:

Server response:

The URL of the location is expanded by the client to http://www.example.com/articles/.

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