← Chrome 152 reference

v152 · privacy-sandbox · ads · deprecation

Deprecate and remove: Attribution Reporting API

Chrome 152 begins the stepped removal of the Attribution Reporting API (ARA), a Privacy Sandbox API designed to measure ad conversions without third-party cookies. Following Chrome's decision to maintain third-party cookies, ARA and other Privacy Sandbox APIs are being removed.

Deprecation / removal: The Attribution Reporting API is being removed from Chrome. Ad measurement integrations built on ARA should plan migration back to existing cookie-based or server-side measurement approaches.

at a glance

Shipped inChrome 152 (Stepped rollout — removal begins)
StatusDeprecation / removal in progress
Standards position (Firefox)No signal
Standards position (Safari)No signal
ChromeStatus6320639375966208 — Deprecate and remove: Attribution Reporting API
Source: chromestatus.com/feature/6320639375966208

background

The Attribution Reporting API (ARA) was a Privacy Sandbox proposal that allowed ad networks to measure click and view conversions without third-party cookies or cross-site tracking. It used two report types:

ARA was designed as a privacy-preserving replacement for cookie-based measurement in a cookieless future. Following Google's announcement that Chrome will maintain support for third-party cookies, the core motivation for ARA no longer applies and it is being removed along with other Privacy Sandbox APIs.

Source: chromestatus feature summary; Privacy Sandbox next steps

what is removed

The Attribution Reporting API comprised declarative HTML attributes (such as attributionsrc on <a>, <img>, and <script>), HTTP response headers (Attribution-Reporting-Register-Source and Attribution-Reporting-Register-Trigger), and browser-managed background reporting pipelines. Upon removal, the attributes are ignored by the HTML parser as unrecognized attributes, response headers are discarded without generating reports, and calls do not raise JavaScript runtime exceptions.

ComponentStatus
attributionsrc HTML attribute on <a>, <area>, <img>, <script>Ignored
Attribution-Reporting-Eligible and Attribution-Reporting-Support HTTP headersNo longer sent on outgoing requests
Attribution-Reporting-Register-OS-* HTTP headersNo longer processed
Event-level and aggregatable reportsNo longer sent
Source: blink-dev Intent to Deprecate and Remove (header and element-level facts); chromestatus feature summary

examples and migration

Historical usage of the Attribution Reporting API before deprecation and removal (now inactive; commented out per deprecation rules):

// DEPRECATED & REMOVED in Chrome: Attribution Reporting API surfaces are no longer functional.
// Historically, an anchor or image declared attribution source registration:
// <a href="https://advertiser.example/landing"
//    attributionsrc="https://ad-tech.example/register-source">
//   Click here
// </a>

// The server responded with registration headers:
// Attribution-Reporting-Register-Source: {
//   "destination": "https://advertiser.example",
//   "source_event_id": "1234567890",
//   "expiry": "604800"
// }

// Migration note: Ad measurement integrations must transition back to
// cookie-based or first-party server-side measurement workflows.
Source: WICG Attribution Reporting API specification; ChromeStatus feature 6320639375966208.

browser compatibility

BrowserSupport
ChromeRemoval initiated in Chrome 152/153 (previously enabled by default in Chrome 115)
EdgeRemoval follows Chromium timeline
FirefoxNo signal; never enabled by default
SafariNo signal; never enabled by default

Security and privacy: The Attribution Reporting API was designed as a cross-site measurement mechanism without third-party cookies. Its removal ends the generation and transmission of background attribution reports from the browser, leaving measurement to cookie-based or server-side workflows.

Source: ChromeStatus feature 6320639375966208; blink-dev Intent to Deprecate and Remove.

see also