# Referrer-Policy header — Effect on the Origin header

> The referrer policy also affects whether the user agent sets the {{HTTPHeader("Origin")}} header with the request's origin or as null (as well as the {{HTTPHeader("Referer")}} header).

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-mdn-714211a2936839e02b94>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:31:45.917329+00:00`
- Tags: `reference-seed`, `mdn`, `web`, `http`, `reference`, `headers`, `referrer-policy`, `header`, `effect`, `origin`

## Provenance

- Source: <https://github.com/mdn/content/blob/d14bee540b5305ddeb93969618ba05102b648bb6/files/en-us/web/http/reference/headers/referrer-policy/index.md>
- Source name: MDN Web Docs
- Source revision: `d14bee540b5305ddeb93969618ba05102b648bb6`
- Source license: `CC-BY-SA-2.5`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

The referrer policy also affects whether the user agent sets the {{HTTPHeader("Origin")}} header with the request's origin or as null (as well as the {{HTTPHeader("Referer")}} header).

Requests using GET or HEAD, or made in cors, websocket, or webtransport mode, are never affected: if the user agent sends an Origin header for them at all, it sends the request's origin, regardless of the referrer policy.

For other requests — such as HTML form submissions or fetch() calls using mode: "same-origin" or "no-cors" — the user agent sets Origin to null when the referrer policy is

no-referrer. no-referrer-when-downgrade, strict-origin, or strict-origin-when-cross-origin, and the request goes from an https origin to a URL that isn't https. same-origin, and the request is cross-origin.

Any other policy value leaves the Origin header set to the request's origin.

&gt; [!NOTE] &gt; Because fetch() defaults to mode: "cors", a same-origin fetch() POST always sends its real Origin, even under Referrer-Policy: no-referrer. The null-Origin behavior above therefore mainly applies to navigate-mode requests, like HTML form submissions, rather than to fetch() calls.

Attribution: Adapted from MDN Web Docs under CC-BY-SA-2.5. Adaptation: WikiKV selected one documentation section, normalized formatting, retained bounded excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.