Attribution Reporting API

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The Attribution Reporting API enables developers to measure conversions — for example when a user clicks an ad embedded on one site and then proceeds to purchase the item over on the vendor's site — and then access reports on those conversions. It does this without relying on third-party tracking cookies.

Concepts and usage

Advertisers commonly want to measure how many users see an ad and then go on to view and purchase a product (conversions). This allows them to figure out what advertising placements are giving them the greatest return on investment (ROI) so they can adjust their advertising strategy accordingly. The process of measuring conversions usually includes capturing data such as:

  • Which users converted (for example purchased an item, or signed up for a service), and how many.
  • The geographic regions they are based in.
  • What sites the ads were placed on.
  • How many products were sold, services were signed up for, etc.
  • How much revenue was generated.

Traditionally on the web, conversion has been measured using third-party tracking cookies. An ad will typically be embedded on a web page in an