Limit Ad Tracking (LAT)

What Is Limit Ad Tracking (LAT)?

Limit Ad Tracking (LAT) was a privacy setting on Apple’s iOS that allowed users to opt out of personalized advertising and cross-app tracking. Introduced in iOS 10 (2016), LAT prevented app developers and advertisers from accessing a user’s Identifier for Advertisers (IDFA). When enabled, the IDFA was replaced with a string of zeros (00000000-0000-0000-0000-000000000000), effectively “zeroing out” the device’s advertising identity. This made it impossible for ad networks and measurement partners to link a device to specific ad interactions or build behavioral profiles for targeting.

LAT was the primary privacy control on iOS until the release of iOS 14.5 in April 2021, when Apple introduced App Tracking Transparency (ATT) and deprecated the LAT setting. Today, LAT is only relevant for devices running iOS versions prior to 14, but understanding it remains essential for interpreting historical attribution data and appreciating how iOS privacy has evolved.

How limit ad tracking works

Limit Ad Tracking, or LAT, is a privacy feature that allows users to control how their device identifiers are used for advertising and measurement. When a user enables LAT, the device’s advertising identifier, such as IDFA on iOS or GAID on Android, is no longer shared in a usable form.

Instead of providing a unique identifier that can be linked to specific users or ad interactions, mobile measurement partners and advertisers receive a blank or zeroed-out identifier. This prevents tracking at the individual user level and makes it difficult to connect app installs, in-app events, or other post-install actions to a specific user or ad campaign.

Why limit ad tracking matters

Limit Ad Tracking plays a crucial role in protecting user privacy. By giving individuals control over how their data is used for advertising and measurement, LAT prevents the creation of detailed user profiles and reduces the ability to deliver personalized ads.

Benefits of LAT for user privacy include:

• Gives users control over the use of their data for advertising

• Reduces the ability to track individuals across apps and campaigns

• Prevents the building of detailed user profiles

• Encourages privacy-first approaches to mobile advertising and measurement

• Supports compliance with data protection regulations such as GDPR and CCPA

Impact of limit ad tracking on attribution

LAT has a significant impact on how advertisers, marketers, and mobile measurement partners can measure performance. With user-level identifiers restricted, deterministic attribution is limited or impossible. Businesses must rely more on aggregated, probabilistic, or modeled attribution methods.

Key impacts of LAT include:

• Restricts access to IDFA and GAID for targeted advertising

• Limits user-level attribution and post-install tracking

• Increases reliance on aggregated or probabilistic attribution techniques

• Reduces precision in measuring campaign performance

• Encourages the adoption of privacy-first measurement strategies that comply with regulations

Understanding how LAT works and its implications is essential for marketers and app developers who want to balance user privacy with accurate campaign measurement.