How Google Changed Tracking, 2013–2025
Every change Google made to tracking in Chrome and on Android, from the Advertising ID to the Privacy Sandbox, three delays, the reversal and the retirement.
Last updated October 23, 2026
Google spent most of a decade planning to end cross-site tracking and then largely didn't. This page sums up where that leaves marketers today, then shows each change against the full timeline.
Where Things Stand on Chrome and Android
The changes add up to a clear picture for marketers in 2026. Here is what still works, function by function.
Third-Party Cookies Work in Most of Chrome.
Google kept third-party cookies and dropped the prompt that would have asked users about them, so Chrome on desktop and Android still allows them by default. The exceptions matter: Chrome on iPhone runs on Apple's engine and blocks them, and so do Incognito windows. Split Chrome traffic by device before relying on cookie-based numbers.
The Replacements Are Mostly Gone.
Google retired Topics, Protected Audience and Attribution Reporting on both Chrome and Android in October 2025, after few companies adopted them. CHIPS and FedCM, which other browsers also support, remain. Treat any vendor plan that still depends on the retired APIs as out of date.
Android Apps Still Run on the Advertising ID.
The Advertising ID remains the basis of Android app targeting and attribution. A user who deletes it returns zeros, and permanent identifiers such as the IMEI have been off-limits since Android 10. The Privacy Sandbox on Android that was meant to replace the ID was retired with the rest, so Android remains far more measurable than iPhone.
Google's Own Ads Run on First-Party Data and Consent.
Google won't use alternative identifiers in its ad products, so email-based IDs from third parties don't help there. In Europe, its measurement and remarketing depend on Consent Mode v2 signals. And while its policies no longer ban fingerprinting, privacy law still requires consent for it in the UK and EU.
What Sets Google Apart
Google announces long before it acts and adjusts as it goes. Its cookie deadline moved in 2021, 2022 and 2024 before the plan was dropped, and each change ran under the oversight of the UK's competition regulator. Google itself put the last delay down to divergent feedback from the industry, regulators and developers, and that tension never resolved.
For marketers, that means reading Google's announcements as a direction, not a date, and watching regulators as closely as Google's own blogs.
Where These Changes Fit
Changes on this page, in platform colours Other changes on How Ad Tracking Changed
All 21 changes
- Oct 31, 2013 · Google Play services 4.0Android Gets a Resettable Advertising IDAndroid's answer to the IDFA, with an opt-out of interest-based ads
- Sep 2019 · Android 10Android 10 Locks Away Permanent Device IdentifiersApps can no longer read the IMEI or serial number
- Jan 14, 2020 · AnnouncementChrome Plans to Phase Out Third-Party CookiesGoogle commits to removing third-party cookies within two years
- Mar 3, 2021 · Google AdsGoogle Says Its Ads Won't Use Alternative IdentifiersNo email-based or other cross-site IDs in Google's ad products once cookies go
- Jun 24, 2021 · AnnouncementChrome Delays the End of Third-Party Cookies to 2023Third-party cookies get a reprieve until late 2023
- Jan 2022 · Privacy SandboxGoogle Replaces FLoC with the Topics APIInterest-based ads to come from browser-assigned topics
- Feb 11, 2022 · UK CMAUK Regulator Accepts Google's Privacy Sandbox CommitmentsChrome cookie changes put under competition oversight
- Feb 16, 2022 · AnnouncementGoogle Announces the Privacy Sandbox on AndroidPlan to limit sharing data with third parties, including the Advertising ID
- Apr 2022 · Google Play servicesAndroid Zeroes the Advertising ID for Users Who Opt OutOpted-out users return a string of zeros, as on iOS since 2016
- Jul 27, 2022 · AnnouncementChrome Delays the End of Third-Party Cookies to 2024Phase-out moved to the second half of 2024
- Jul 1, 2023 · Google AnalyticsGoogle Analytics 4 Replaces Universal AnalyticsEvery Google Analytics user moved to a new data model, and old data was deleted a year later
- Sep 7, 2023 · Privacy SandboxChrome Ships the Privacy Sandbox APIsCookie-free targeting and measurement APIs on by default for most Chrome users
- Jan 4, 2024 · Tracking ProtectionChrome Turns Off Third-Party Cookies for 1% of UsersThird-party cookies restricted for 1% of Chrome users
- Mar 2024 · EU Digital Markets ActGoogle Requires Consent Mode V2 for EEA TrafficEEA ad measurement and personalization need consent signals
- Apr 23, 2024 · AnnouncementChrome Delays the End of Third-Party Cookies a Third TimePhase-out moved from late 2024 to 2025
- Jul 22, 2024 · AnnouncementGoogle Abandons Removing Third-Party Cookies from ChromeCookie phase-out dropped in favour of a proposed user choice
- Feb 16, 2025 · Google Ads policyGoogle Lifts Its Ban on Fingerprinting in AdsAdvertisers on Google's platforms no longer barred from fingerprinting devices
- Apr 17, 2025 · RulingUS Court Rules Google Illegally Monopolized Ad TechGoogle keeps its ad exchange but must open its auctions to rivals
- Apr 22, 2025 · AnnouncementChrome Drops the Cookie Choice PromptThird-party cookies stay on by default, with no new prompt
- Sep 2, 2025 · RulingUS Court Lets Google Keep ChromeChrome's cookie and tracking policy stays Google's call
- Oct 17, 2025 · Chrome and AndroidGoogle Retires Most of the Privacy SandboxTopics, Protected Audience and Attribution Reporting retired
How It Compares
Apple took the opposite approach. It enforces privacy through the operating system, usually announcing changes in June and switching tracking off for everyone in September, with little room to negotiate. Its tracking prompt and cookie blocking made iPhone the hardest platform to measure, while Google's reversals left Chrome the easiest.
For marketers working across both, the same campaign is measured two ways: aggregated and partly modelled on iPhone, and still largely cookie- and ID-based on Chrome and Android.
Measurement That Keeps Up with Every Tracking Change
Bconic combines attribution, incrementality and marketing mix modelling, so you can see what your marketing drives on every platform, whatever changes next.