v144 · miscellaneous

Deprecate and remove: Attribution Reporting API

The Attribution Reporting API is a privacy-preserving web API designed to measure ad conversions without third-party cookies or user tracking across sites.

concepts

  1. Attribution Removal

    Attribution Reporting API is removed. Conversion measurement moves back to first-party logging or server-side correlation against logged-in users.

  2. Migration Probe

    Run the probe to see which Attribution Reporting surfaces are still exposed in this build, paired with a migration cheatsheet pointing to server-side conversion APIs.

  3. First-party Recipe

    The migration shape, end to end: impression → click ID in URL → landing → conversion, with hashing and aggregation toggles, and a live console showing the JSON your server would receive.

  4. Migration Timeline

    An interactive checklist of the four migration phases — detect, server fallback, redirect, remove — with a live feature-detection probe and code snippets for each step.

why it shipped

Chrome has announced that the current approach to third-party cookies will be maintained. Given this, we expect adoption to decrease over time as cross-site measurement will remain possible in Chrome using third-party cookies.

references