02.01.26

How mobile apps track you without cookies (and how to take back control)

When you think of tracking, you probably think of browser cookies. But here’s the catch: mobile apps don’t rely on traditional cookies. Instead, many advertising and analytics companies use device-based identifiers to follow your activity across apps on the same phone or tablet. Two of the most common are Apple’s Identifier for Advertisers (IDFA) and Google’s Advertising ID (AAID/GAID). Together, they help companies measure engagement, attribute ad campaigns, and build ad profiles—often without you ever touching a browser.

How App Tracking Works in Plain English

  • Unique device IDs: Your phone provides a resettable ad ID (like IDFA or GAID). It’s not your name, but it is unique enough to recognize your device over time.
  • SDKs inside apps: Many apps include third‑party software development kits (SDKs) for analytics, ads, crash reporting, and personalization. These SDKs read the ad ID and send usage events (e.g., “opened app,” “clicked button,” “made purchase”) back to the provider.
  • Cross‑app stitching: Because the same ad ID can appear in multiple apps, advertising networks can connect behavior across different apps on your device and build a richer profile (interests, likely demographics, purchase intent).
  • Attribution & targeting: Marketers use this data to decide which ads to show you and to measure whether an ad led to an app install or purchase.

Is This the Same as Cookies?

Not exactly. Cookies live in your browser and can be cleared. App tracking relies on system‑level identifiers that work outside the browser. That’s why deleting cookies won’t stop app tracking. The good news? Both iOS and Android give you controls to limit or reset these identifiers.

Your Controls on iOS (iPhone/iPad)

  • App Tracking Transparency (ATT): Since iOS 14.5, apps must ask permission to “track you across other companies’ apps and websites.” If you tap “Ask App Not to Track,” the app can’t access your IDFA for cross‑app tracking.
  • Turn off tracking globally: Go to Settings → Privacy & Security → Tracking and toggle off “Allow Apps to Request to Track.”
  • Reset or limit ad personalization: In Settings → Privacy & Security → Apple Advertising, disable personalized ads.
  • Review app permissions: In Settings → Privacy & Security, audit Location, Contacts, Photos, Bluetooth, Local Network—excess access can increase your data exhaust.

Your Controls on Android

  • Opt out of Ads Personalization: Go to Settings → Privacy → Ads (path varies by device) and Opt out of ad personalization.
  • Reset or delete the Advertising ID: In the same Ads screen, Reset or Delete Advertising ID so apps can’t continue using the old identifier.
  • Permissions check‑up: In Settings → Privacy → Permission manager, review Location, Phone, Contacts, Storage and turn off what isn’t essential.
  • Limit background data: In Settings → Network & internet → Data usage, restrict background data for apps that don’t need it.

Smart Habits to Reduce Tracking

  • Be picky with installs: Fewer apps = fewer SDKs tracking you.
  • Sign in only when needed: Using sign‑in across many apps can tie activity back to your account.
  • Use privacy‑focused alternatives: Some apps (and browsers with strong anti‑tracking) collect less by design.
  • Read the privacy labels/policies: Check what data the app collects (location, identifiers, usage data) before installing.
  • Keep OS and apps updated: Platforms continue to tighten privacy—updates bring better controls.

Mobile app tracking relies on device identifiers—not cookies—to link behavior across apps. The silver lining: you have real controls. Take five minutes today to review your tracking permissions, reset your ad ID, and uninstall what you don’t use. You’ll still enjoy your favorite apps—just with more privacy and less profiling.