Hi Peter, The changes to APIs at the Android level are outside the scope of this intent. As mentioned in this intent, Attribution-Reporting-Register-OS-* headers will no longer be processed after removal of the ARA API.
Best, Nan On Tuesday, November 18, 2025 at 5:04:07 AM UTC-5 Peter Beverloo wrote: > This is great, good luck with the deprecation! > > This feature is exposed on Android WebView as well, including an API for > Android apps, do you expect to deprecate those in line with this effort? > > Thanks, > Peter > > > On Wed, Nov 12, 2025 at 11:05 PM Mike Taylor <[email protected]> > wrote: > >> LGTM3 to deprecate. >> On 11/13/25 1:44 a.m., Daniel Bratell wrote: >> >> LGTM2 for deprecation (not for the actual removal) >> >> /Daniel >> On 2025-11-12 17:28, Vladimir Levin wrote: >> >> LGTM1 to deprecate. This feature removal sounds riskier than other >> related features, especially coupled with 20% page loads. So although the >> plan to monitor for 6 milestones sounds good, this approval does *not* >> extend to removal. Please come back to this thread closer to the proposed >> removal to see if the usage had dropped substantially. >> >> On Sunday, November 9, 2025 at 7:47:04 PM UTC-5 Mike Taylor wrote: >> >>> Could you please request Debuggability and Testing bits in your >>> chromestatus entry >>> On 11/8/25 3:35 a.m., Nan Lin wrote: >>> >>> Intent to Deprecate and Remove: Attribution Reporting API >>> >>> Contact emails >>> >>> [email protected], [email protected], [email protected] >>> >>> Explainer >>> >>> https://github.com/WICG/attribution-reporting-api >>> >>> Specification >>> >>> https://wicg.github.io/attribution-reporting-api/ >>> >>> Summary >>> >>> The Attribution Reporting API (ARA) is a privacy-preserving web API >>> designed to measure ad conversions without third-party cookies or user >>> tracking across sites. >>> >>> Following Chrome's announcement >>> <https://privacysandbox.com/news/privacy-sandbox-next-steps/> that the >>> current approach to third-party cookies will be maintained, we are now >>> planning to deprecate and remove >>> <https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/> >>> >>> the Attribution Reporting API (along with certain other Privacy Sandbox >>> APIs, as outlined on the Privacy Sandbox feature status page >>> <https://privacysandbox.google.com/overview/status>). >>> >>> Blink component >>> >>> Internals > AttributionReporting >>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Internals%3EAttributionReporting> >>> >>> Web Feature ID >>> >>> None >>> >>> Motivation >>> >>> Chrome has announced >>> <https://privacysandbox.com/news/update-on-plans-for-privacy-sandbox-technologies/> >>> >>> that the current approach to third-party cookies will be maintained. Given >>> this, we expect adoption of the Attribution Reporting API to decrease over >>> time, as cross-site measurement will remain possible in Chrome using >>> third-party cookies. Further, although Microsoft Edge integrates with the >>> Attribution Reporting API, most other browser engines have not signaled >>> interest in launching the API. Removing this (and certain other Privacy >>> Sandbox APIs <https://privacysandbox.google.com/overview/status>) will >>> help focus efforts on the proposed interoperable Attribution >>> <https://github.com/w3c/attribution> standard. >>> >>> Developer-facing impact >>> >>> Sites that are using the Attribution Reporting API for conversion >>> measurement and do not migrate to alternative solutions may experience a >>> disruption in conversion measurement on eventual removal of the API code >>> from Chrome. >>> >>> >>> - >>> >>> Conversion measurement disruption: All ad conversion events relying >>> on the deprecated API will fail to register or report. Sites using this >>> API >>> as their primary or supplementary method for ad measurement will lose >>> visibility into campaign performance metrics derived from this >>> technology. >>> - >>> >>> Public API surface: The following outlines the consequences of >>> deprecating and removing the Attribution Reporting API for each of the >>> interfaces defined here >>> <https://wicg.github.io/attribution-reporting-api/#idl-index>. >>> - >>> >>> Potentially user-breaking >>> - >>> >>> XMLHttpRequest.setAttributionReporting(): Calling >>> setAttributionReporting() on an XMLHttpRequest object will >>> throw an exception because the method will no longer exist. This >>> is a >>> breaking change for any site that calls this method. Given that >>> this >>> feature is not implemented in other browsers, it is likely that >>> sites are >>> already using feature detection to check the method’s existence >>> before >>> calling it, which would prevent breakage. We will start to track >>> the usage >>> of this method. >>> - >>> >>> Non user-breaking >>> - >>> >>> HTMLAttributionSrcElementUtils and the attributionsrc >>> attribute: The attributionsrc attribute on <a>, <area>, <img>, >>> and <script> elements will be ignored. Any values assigned to this >>> attribute will have no effect, and the browser will no longer >>> initiate >>> background requests to register attribution sources/triggers. >>> Additionally >>> we will no longer process trigger headers on legacy subresource >>> requests >>> that lack the opt-in (either on an element or fetch/XHR). This >>> will not >>> cause any visible breakage or errors on the page for the user, but >>> it will >>> silently prevent conversion measurement for sites that rely on >>> this >>> attribute. >>> - >>> >>> attributionsrc in window.open(): The attributionsrc feature in >>> the features string of a window.open() call will be ignored. >>> The window will still open as requested, but no attribution source >>> will be >>> registered. This will not cause any visible breakage or errors on >>> the pages >>> for the user, but it will silently prevent conversion measurement >>> for sites >>> that rely on this functionality. >>> - >>> >>> AttributionReportingRequestOptions and the attributionReporting >>> member in RequestInit: The attributionReporting property >>> within the options of a fetch() call will be ignored. The fetch >>> request >>> will still be made, but it will not trigger any >>> attribution-related >>> functionality. This change will not cause any JavaScript errors, >>> but >>> conversion measurement that relies on the fetch requests will no >>> longer >>> work. >>> - >>> >>> Attribution-Reporting-Eligible and >>> Attribution-Reporting-Support headers: Since the browser will >>> no longer process the attributionsrc attribute or the >>> attributionReporting property in requests, it will no longer >>> send these two headers on outgoing requests. >>> - >>> >>> attribution-reporting permission policy: The >>> attribution-reporting permission policy >>> >>> <https://wicg.github.io/attribution-reporting-api/#permission-policy-integration> >>> >>> will be removed along with the API. Since the API it controls will >>> no >>> longer exist, the permission policy will have no effect and its >>> removal is >>> not considered a breaking change. >>> >>> >>> >>> Planning and Estimated Milestones >>> >>> Deprecate the browser API surface in M144 and remove in M150. >>> >>> There will be one aspect of ARA that will end sooner. Server-side >>> summary report computation will no longer operate by late December 2025. We >>> have already communicated to the users of that service of these plans. Such >>> users can use debug reports instead until the removal of the ARA surface as >>> a whole. Since this impacts post-facto server-side operations, it will not >>> incur any user-facing breakage. >>> >>> Currently ~20% >>> <https://chromestatus.com/metrics/webfeature/timeline/popularity/282> >>> of page loads use the Attribution Reporting API. While ARA’s usage as a >>> percentage of page loads is quite high, it is driven by a small number of >>> third-party ad tech scripts present on a large number of sites. We will >>> continue to monitor usage in addition to providing comprehensive updates on >>> privacysandbox.google.com with the status of the API and deprecation >>> plans <https://privacysandbox.google.com/overview/status>. >>> >>> We will proactively work toward reducing ARA usage to low levels once >>> this intent is approved, including disallowing any new enrollment sign-ups, >>> and contacting enrolled sites to inform them about the deprecation >>> timelines. >>> >>> Link to entry on the Chrome Platform Status >>> >>> https://chromestatus.com/feature/6320639375966208 >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "blink-dev" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to [email protected]. >>> To view this discussion visit >>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/beb44d6a-aae5-4664-994a-38fb93bb4580n%40chromium.org >>> >>> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/beb44d6a-aae5-4664-994a-38fb93bb4580n%40chromium.org?utm_medium=email&utm_source=footer> >>> . >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/54acf866-c208-4770-a3bc-0d8100a97fban%40chromium.org >> >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/54acf866-c208-4770-a3bc-0d8100a97fban%40chromium.org?utm_medium=email&utm_source=footer> >> . >> >> -- >> You received this message because you are subscribed to the Google Groups >> "blink-dev" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> > To view this discussion visit >> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/d78e1296-89b1-432e-8f59-cd0c9cda9325%40chromium.org >> >> <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/d78e1296-89b1-432e-8f59-cd0c9cda9325%40chromium.org?utm_medium=email&utm_source=footer> >> . >> > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/968d07e8-1aff-4c47-9e41-cd2785567a9en%40chromium.org.
