CSP: referrer

The HTTP Content-Security-Policy (CSP) referrer directive used to specify information in the Referer header (with a single r as this was a typo in the orignal spec) for links away from a page. This API is deprecated and removed from browsers.

Syntax

Content-Security-Policy: referrer <referrer-policy>;

where <referrer-policy> can be one of the following values:

"no-referrer"

The Referer header will be omitted entirely. No referrer information is sent along with requests.

"none-when-downgrade"

This is the user agent's default behavior if no policy is specified. The origin is sent as referrer to a-priori as-much-secure destination (HTTPS->HTTPS), but isn't sent to a less secure destination (HTTPS->HTTP).

"origin"

Only send the origin of the document as the referrer in all cases.
The document https://example.com/page.html will send the referrer https://example.com/.

"origin-when-cross-origin" / "origin-when-crossorigin"

Send a full URL when performing a same-origin request, but only send the origin of the document for other cases.

"unsafe-url"

Send a full URL (stripped from parameters) when performing a a same-origin or cross-origin request. This policy will leak origins and paths from TLS-protected resources to insecure origins. Carefully consider the impact of this setting.

Examples

Content-Security-Policy: referrer "none";

Specifications

Not part of any specification.

Browser compatibility

See also

• Content-Security-Policy
• Referrer-Policy header
• Referer header