GAID (Google Advertising ID)

GAID (Google Advertising IDGlossaryDevice IDA unique identifier assigned to a mobile device (or its advertising profile) used to recognize the same device across apps and sessions — the backbone of determinist...), also called Android Advertising ID or AAID, is Google's per-device advertising identifier on Android. Conceptually, it's the equivalent of Apple's IDFAGlossaryIdentifier for Advertisers (IDFA)Apple's per-device advertising identifier — historically used for deterministic ad attribution, now only available when the user explicitly opts in via App Tracking... — a UUID Google assigns to each Android device for ad-tracking purposes, accessible to apps via the Google Play Services SDKGlossarySDK (Software Development Kit)A packaged set of code, libraries, and tools a developer drops into an app to add a capability — the integration unit for attribution, analytics, ads, and monetizati.... The big difference from iOS post-ATTGlossaryApp Tracking Transparency (ATT)Apple's iOS 14.5+ framework requiring apps to display a system prompt and obtain user consent before accessing the IDFA or tracking the user across other apps and we...: GAID is still broadly available in 2026, with opt-out rates much lower than iOS ATT opt-out.

Opt-out reality on Android (2026 anchors):

• Users can reset GAID or opt out entirely via Settings → Google → Ads → Delete advertising ID.
• Typical opt-out rate: 10-20% globally, with significant geographic variation.
• This is dramatically lower than iOS ATT opt-out (60-80%) — Android users mostly leave GAID enabled because the opt-out is hidden deeper in Settings (no app-triggered prompt) and there's no system-wide pushGlossaryPush NotificationA message delivered to a user's device from your app's server — the single biggest re-engagement lever in mobile, when done well, and a fast path to uninstall when d... for opt-out the way Apple created with ATT.

Result: Android attribution remains primarily deterministic via GAID matching in 2026, while iOS attribution is primarily SKANGlossarySKAdNetwork (SKAN)Apple's privacy-preserving attribution framework for iOS — returns install credit to ad networks with a deliberate delay and aggregation, without exposing any device...-aggregated.

How GAID is used in mobile attribution

1. 01At ad click: the ad networkGlossaryAd NetworkA platform that aggregates ad demand from many advertisers and matches it to publisher inventory through real-time auctions.'s SDK in the publisher app reads the user's GAID and includes it in the click record.
2. 02At install: the MMPGlossaryMobile Measurement Partner (MMP)A third-party attribution provider (AppsFlyer, Adjust, Singular, Branch, Kochava) that adjudicates which ads drove which installs across multiple ad networks, with i... SDK in the freshly installed app reads the GAID on first launch and reports it to the MMP.
3. 03Matching: the MMP matches the install's GAID against click records from all integrated ad networks within the configured attribution windowGlossaryAttribution WindowThe time period after an ad click or impression during which an install will still be credited to that ad — the lookback window that defines what counts as "caused b....
4. 04Attribution decision: the click record with the most recent matching GAID (within window) gets credit.

This is the same deterministic attribution model that worked on iOS pre-ATT. It's not perfect (GAID can be reset, opt-out users get null GAID) but works for the 80-90% of Android users with valid GAID.

Privacy SandboxGlossaryPrivacy Sandbox (Android)Google's multi-year initiative to introduce privacy-preserving alternatives to GAID-based ad tracking on Android — the platform's eventual SKAN equivalent. for Android — the upcoming change: Google announced Privacy Sandbox for Android in 2022 with a multi-year phased rollout. The architecture is similar to Apple's SKAN: aggregated, privacy-preserving attribution that doesn't expose device-level identifiers. Key components: Attribution API (SKAN-like aggregated install attributionGlossaryInstall AttributionThe process of assigning credit for a new install to the ad, campaign, and network that drove it — so advertisers know what's working and can compensate networks acc...), Topics API (interest-based ad targeting via on-device ML), Protected Audiences API (on-device audience activationGlossaryActivationThe percentage of installs who complete a defined "activation event" — the action that converts a passive install into an active user.). Rollout timing as of 2026: Privacy Sandbox is in beta with developer testing; Google has signaled a phased deprecation of GAID over multiple years, with full rollout expected ~2027. The mobile-ad-tech industry is preparing for an Android version of the iOS-2021 ATT shift, but with more lead time and more publisher / advertiser input on the design.

Strategic implications for mobile-app advertisers

• Right now (2026): Android attribution still primarily deterministic. Allocate UAGlossaryPaid UA (Paid User Acquisition)Mobile app user acquisition via paid advertising channels — Meta, TikTok, Google, AppLovin, ironSource, and other ad networks. budget knowing Android measurement is cleaner / faster than iOS.
• Through 2027: prepare for Privacy Sandbox migration. Major MMPs (AppsFlyer, Adjust, Singular) are building Privacy Sandbox support; integrate early.
• Post-2027: Android attribution will mirror iOS — patchwork of aggregated Privacy Sandbox attribution + first-party signal + opt-in deterministic for the minority who keep GAID enabled.
• First-party investment: regardless of platform timing, investment in first-party signal (CRM, web-to-appGlossaryWeb-to-AppA user acquisition flow where users discover and engage with your product via web first, then are converted to install the mobile app — often with deferred deep link..., owned-channel) pays off across iOS and Android.