Activate-Storage-Access

Servers answering embedded cross-site requests control storage access activation through the Activate-Storage-Access response header. The header answers the Sec-Fetch-Storage-Access request signal, telling the browser to activate the context's cookie permission or to retry the request with credentials attached.

Usage

Embedded content holding a storage access permission still loads without its unpartitioned cookies until the permission activates. Before the header existed, activation required the embed to run document.requestStorageAccess() in script and reload itself. The header moves the decision to the server: a response to a request reporting Sec-Fetch-Storage-Access: inactive names the activation the server wants, and the browser handles the rest without any script in the embed.

The header applies only where permission already exists. A request reporting none has nothing to activate, and the browser ignores the header on such responses. Granting the permission in the first place still runs through the Storage Access API prompt or a related grant.

Values

retry

The server asks the browser to activate storage access and repeat the request with unpartitioned cookies included. The allowed-origin parameter names the embedding origin permitted to trigger the retry, and a wildcard covers any embedder.

Activate-Storage-Access: retry; allowed-origin="https://site.example.re"

load

The server accepts the load and asks the browser to activate storage access for the resulting context, without repeating the request. Fitting for document loads where the embed continues with active access.

Activate-Storage-Access: load

Example

An embedded widget request arrives without cookies while permission exists. The server requests a credentialed retry, and the repeated request carries the cookies with Sec-Fetch-Storage-Access: active.

Response to the first request

HTTP/1.1 401 Unauthorized
Activate-Storage-Access: retry; allowed-origin="https://site.example.re"
Vary: Sec-Fetch-Storage-Access

Responses differing by storage access state carry Vary: Sec-Fetch-Storage-Access so caches separate the credentialed and uncredentialed answers.

See also

Last updated: September 21, 2026