Using Related Website Sets with the Storage Access API for seamless data sharing

Combining Related Website Sets with the Storage Access API creates a more streamlined and user-friendly experience for sharing data across related websites, as illustrated in the following example:

RWS creation  A beauty company with multiple sites adds its domains to a Related Website Set.

Cross-site navigation  A person visits a site in that set, BeautyA.com, and searches for makeup. Later, that person visits another site, BeautyB.com, also from that set.

Site experience optimization BeautyB.com relies on cookies from BeautyA.com to manage things like log-in and customized product recommendations. When the site loads, BeautyA.com uses Storage Access to request access to its cookies. Since the sites are in the same Related Website Set, access is automatically granted.

Benefits of combining Related Website Sets with the Storage Access API:

• Improved user experience: Users enjoy a smoother experience with features like single sign-on across related websites.
• Enhanced functionality: Websites can offer personalized content and services, such as customized product recommendations, based on user activity across related sites.
• Cross-browser fallback: Related Website Sets is underpinned by Storage Access, which has wide browser support, making this a robust solution with broader compatibility (refer to Mozilla's description of Storage Access and its benefits in MDN). Chrome's implementation of Storage Access within Related Website Sets is designed to align with these existing standards, promoting cross-browser compatibility. See Browser support for Related Website Sets for more details on Chrome's approach.

How Related Website Sets enhances Storage Access:

• Automatic access: When websites within the same Related Website Sets use Storage Access, the permission prompt is bypassed, and access is automatically granted.
• Expanded capabilities: Related Website Sets enables Storage Access to provide cookie access to non-iframe resources, expanding its functionality beyond iframes.

Sample use cases for Related Website Sets with Storage Access:

• Single sign-on: Maintain a single login session across multiple related websites or country domains.
• Embedded service login: Allow users to seamlessly log in to embedded services from related sites.
• Personalized recommendations: Offer customized product or content recommendations based on user activity across related sites.