Storage Access API

Third-party cookie blocking by browsers, user settings, and storage partitioning, pose a challenge for sites and services that rely on cookies and other storage in embedded contexts, for user journeys such as authentication. The Storage Access API (SAA) allows these use cases to continue to work, while limiting cross-site tracking as much as possible.

Implementation status

The Storage Access API is available in all major browsers, but there are slight implementation differences between browsers. These differences have been highlighted in the relevant sections in this post.

Work is continuing to resolve all remaining blocking issues, before standardizing the API.

What is the Storage Access API?

The Storage Access API is a JavaScript API that allows iframes to request storage access permissions when access would otherwise be denied by browser settings. Embeds with use cases that depend on loading cross-site resources can use the API to request access permission from the user, on an as-needed basis.

If the storage request is granted, then the iframe will have access to its unpartitioned cookies and storage, which are also available when users visit it as a top-level site.