Phones give apps identifiers and permissions that can be used to follow you across other companies’ apps and websites for advertising. This guide covers the controls Apple and Google document for limiting that: App Tracking Transparency and iCloud Private Relay on iPhone, the advertising ID on Android, and the permission settings on both.

iPhone

1. Stop apps from tracking you

Since iOS 14.5, apps must ask permission before tracking your activity across other companies’ apps and websites, according to Apple. Apple defines tracking as linking information that identifies you or your device from an app with information from third-party apps, websites and other locations for targeted advertising or ad measurement, or sharing it with data brokers.

  1. Go to Settings, tap Privacy & Security, then tap Tracking.
  2. Turn off permission for any app in the list that you do not want tracking you.
  3. To stop the prompts altogether, turn off Allow Apps to Request to Track. You can then ask every app you previously allowed to stop tracking.

With that setting off, Apple says each app that asks is treated as if you tapped Ask App Not to Track and cannot access the system advertising identifier (IDFA). An app told not to track is also not permitted to track you using other information that identifies you, such as your email address. Apple says you can still use all of an app’s features either way.

2. Turn on iCloud Private Relay

Private Relay is part of an iCloud+ subscription. Apple’s iPhone User Guide says it encrypts traffic leaving the phone and sends it through two separate internet relays, so websites cannot see your IP address and exact location and network providers cannot collect your browsing activity in Safari.

  1. Go to Settings > [your name] > iCloud > Private Relay, then tap Private Relay to turn it on. It must be turned on separately on each device.
  2. Under IP Address Location, choose Maintain General Location to keep seeing local content in Safari, or Use Country and Time Zone to make your location more obscure.
  3. Check your networks. In Settings > Wi-Fi, tap the Actions Available button and make sure Limit IP Address Tracking is on; for mobile data, go to Settings > Cellular, tap Cellular Data Options (or select a line if you have more than one) and turn on the same setting.

3. Review app permissions

  1. Go to Settings > Privacy & Security and tap a category such as Calendars, Reminders or Motion & Fitness.
  2. Turn access off for any listed app that does not need it.
  3. Tap App Privacy Report on the same screen to see how apps use the permissions you granted and their network activity, as Apple describes.

Android

4. Delete or reset the advertising ID

Google’s Play Console documentation describes the advertising ID as a unique, user-resettable and user-deletable ID for advertising, provided by Google Play services. Once you delete it, apps that try to read it receive a string of zeros instead.

  1. Open Settings and tap Privacy > Ads.
  2. Tap Delete Advertising ID and confirm. To swap it for a new one instead, tap Reset Advertising ID.

On some older Android versions, Google says to go to Settings > Privacy > Advanced > Ads and turn on Opt out of Ads Personalization.

5. Use the permission manager

  1. Open Settings and tap Security & Privacy > Privacy > Permission manager, according to Android Help.
  2. Tap a permission type, such as Location, Contacts or Microphone, to see which apps have it.
  3. Tap an app and change its setting. For location, the choices include Allow only while using the app, Ask every time and Don’t allow; All the time lets an app use location even when you are not using it.

6. Pause unused apps

Open Settings, tap Apps, choose an app and, under “Unused app settings,” turn on Pause app activity if unused. Google lists this under automatically removing permissions for unused apps.

Common problems

  • “Allow Apps to Request to Track” cannot be turned on. Apple says this applies to child accounts and users under 18 by birth year, Apple Accounts managed by a school or business, devices with a configuration profile that limits tracking, and Apple Accounts created in the last three days.
  • Private Relay is missing. It requires iCloud+ for you or someone in your Family Sharing group, and Apple says it is not available in all countries or regions.
  • A site misbehaves with Private Relay on. Apple offers Turn Off Until Tomorrow in the Private Relay settings, which turns it back on automatically within 24 hours.
  • Android menus do not match. Google says some steps on Pixel phones work only on Android 11 and up, and older versions use the Advanced menu for ads settings.
  • Ads still look targeted. Google notes that after you delete the advertising ID, apps may have their own settings that can also affect the types of ads you see.

Corrections and tips: email the editor using the address on the Contact page.