ATT is Apple's iOS framework that requires apps to request explicit user permission before tracking their activity across other companies' apps and websites.
App Tracking Transparency (ATT) is an iOS 14.5+ framework that requires every app to display a standardized permission prompt before accessing a device's IDFA (Identifier for Advertisers) or tracking users across apps and websites. Without the user's explicit opt-in, apps cannot perform user-level cross-app attribution or share data with third-party measurement tools at an individual level.
The industry-wide opt-in rate for ATT prompts has settled at 25–45% depending on app category, meaning 55–75% of iOS users cannot be tracked at the user level for attribution purposes. This fundamentally changed iOS UA by reducing the data available for targeting, attribution, and audience building.
For UA teams, ATT means a significant portion of iOS campaigns are measured through SKAN's aggregate signals rather than user-level MMP data. The combination of SKAN-attributed installs and modeled conversions (from Meta's Conversions API) is now the standard iOS measurement approach.
ATT is the single biggest structural change to mobile advertising measurement in the last decade. Teams that don't understand ATT opt-in mechanics and SKAN fallback attribution will systematically misread iOS campaign performance, over-attributing success to opted-in users and under-counting conversions from the majority who opted out.
SKAdNetwork is Apple's privacy-preserving mobile attribution framework for iOS, which reports campaign-level install and conversion data without revealing individual user identity.
Learn moreMobile AttributionAn MMP is an independent third-party platform that attributes app installs and in-app events to the advertising sources that drove them.
Learn moreMobile AttributionProbabilistic attribution assigns conversion credit to ad exposures based on statistical likelihood rather than deterministic device identifiers.
Learn moreMobile AttributionClick-through attribution credits an ad for a conversion when a user clicked the ad and then completed the action within the attribution window.
Learn moreConnect your ad networks and MMP in 5 minutes. AI tags every creative automatically.
Start Free Trial