Docs

Privacy Sandbox Retirement: What to Track Now

Google is retiring most Privacy Sandbox ad APIs on Android and Chrome — track how your attribution numbers shift as fallback methods take over.

Acquisition

Google confirmed in October 2025 that it’s retiring most of the Privacy Sandbox advertising APIs it spent years building — Topics, Protected Audience, Attribution Reporting, On-Device Personalization, Private Aggregation, and several others — across both Chrome and Android. Adoption never reached the level Google needed to justify keeping the stack running, and the industry mostly kept using existing identifiers and server-side workarounds instead. For mobile teams who spent 2023-2025 quietly plumbing Attribution Reporting API calls into their SDKs as an ATT- and GAID-resilient fallback, that work is now heading for the bin, and it’s happening on a rolling basis rather than a single cutover date.

The risk isn’t the retirement itself — it’s not noticing which of your attribution numbers were quietly resting on a Privacy Sandbox API and watching them degrade without an obvious cause. A campaign that looked well-attributed in Q2 can start showing an unexplained rise in “unattributed” or “organic” installs in Q4, and if nobody connects that to an API sunset, the instinct is to blame the ad network or the creative, not the plumbing underneath.

Data Points to Track

  • attribution_source — record which mechanism actually resolved each conversion: SKAdNetwork, GAID/IDFA-based deterministic match, Attribution Reporting API, server-side MMP match, or “unattributed.” Watch the API-based share trend toward zero.
  • unattributed_install_rate by campaign and network, tracked weekly, to catch a sudden step-change rather than a gradual drift you’d otherwise dismiss as noise.
  • api_deprecation_flag — a build-time or config flag on any code path that still calls a retiring Privacy Sandbox API, so you know exactly what’s still live in production.
  • fallback_method_used for conversions that would previously have relied on Attribution Reporting — did they resolve via probabilistic modeling, a clean room, or not at all?
  • sdk_version_at_install joined against your MMP’s changelog, since SDK vendors are shipping their own migrations off Privacy Sandbox on different timelines.

Setup Steps

  1. Audit every SDK and internal service that calls Topics, Protected Audience, Attribution Reporting, or related APIs, and list them with an owner and a removal or replacement date.
  2. Add an attribution_source field to your conversion event schema now, if it doesn’t already exist, so you can see the mix shift before it becomes a mystery.
  3. Baseline your current unattributed/organic rate per major campaign this week, before more APIs go dark, so you have a clean “before” number to compare against.
  4. Check your MMP and ad network dashboards for their own migration notices — most are moving toward server-side conversion APIs, clean rooms, or expanded probabilistic modeling, and the timing of that shift matters for your data.
  5. Set an alert on unattributed-install-rate spikes greater than a set threshold week-over-week, tagged separately from your normal anomaly alerts so it doesn’t get lost.

Actionable Insights

The teams least disrupted by this retirement are the ones who never let a single attribution mechanism become invisible infrastructure — they can already say, for any given conversion, which method resolved it and what happens if that method disappears. If your attribution_source breakdown shows a growing “unattributed” bucket with no matching change in your API call logs, the cause is almost certainly upstream: an ad network or MMP has already flipped its own fallback before telling you. Treat this retirement as a forcing function to consolidate onto server-side conversion tracking and first-party data wherever you can, since it’s the one attribution layer that doesn’t depend on which experimental browser or OS API happens to still be funded next year.

Expert help

Need help tracking this in your app?

Our team sets up analytics pipelines for mobile and web teams every day. Talk to us and get your first events flowing in under an hour.

Talk to an expert