Resetting the advertising ID

A smartphone’s advertising ID is a unique tracker assigned to the device. It lets companies build a profile of app usage, interests and behaviour without anyone logging in anywhere. Resetting it regularly disrupts that profile.

The advertising ID

An advertising ID lets apps and ad networks link activity across services to target ads.

  • Android: the Google Advertising ID (GAID)

  • iOS: the Identifier for Advertisers (IDFA)

A search for “hiking boots” in one app can surface boot ads in another later, with no login involved, because both saw the same ID.

The gain from a reset

  • Resetting mints a new random ID, which breaks the chain that builds a long-term profile.

  • Ads still appear, but with less targeting.

  • It helps even without opting out, since some apps ignore the “opt out of ads personalisation” setting but still use the ID for analytics.

On Android

  • Open Settings, Google, Ads

  • Tap Reset advertising ID

  • Optionally enable “Opt out of ads personalisation” to limit tracking further

Some Android skins (Samsung, Xiaomi) bury this setting; searching Settings for “advertising ID” finds it.

On iOS

  • Open Settings, Privacy and Security, Tracking

  • Turn off “Allow Apps to Request to Track”, which blocks IDFA access entirely

  • Current iOS has no separate reset button (it was removed in iOS 14); with tracking turned off the IDFA is replaced by zeros, which achieves the same thing

Limitations

  • It does not stop all tracking; fingerprinting, IP logging and first-party data (logged-in tracking by Google or Facebook) still work.

  • Some apps bypass it, especially when the same Google or Apple account is used everywhere.

  • Resets are not instant; ad networks can take hours to update.

Stronger measures

  • A firewall app such as TrackerControl for Android blocks hidden trackers.

  • Google’s own ad personalisation can be adjusted at myadcenter.google.com.

  • On iOS, Lockdown Mode (Settings, Privacy and Security, Lockdown Mode) hardens the device against targeted spyware; it is aimed at that threat rather than at everyday ad tracking.

Automating it

  • On Android, Tasker or MacroDroid can reset the ID weekly.

  • On iOS, the Shortcuts app cannot reset the IDFA, but a weekly reminder covers it.

A weekly reset, paired with Firefox Focus for private browsing and NextDNS or AdGuard for ad and tracker blocking, fragments the data enough to reduce profiling. It does not confer invisibility.

Testing

Last reviewed: 2026-07-08.