Find, Reset or Delete Your Mobile Advertising ID

Android phones have a Google advertising ID that you can view, reset or delete under Settings > Google > All services > Ads (Settings > Privacy > Ads on some phones); after deletion, apps that ask for it get a string of zeros. iPhones have an IDFA that iOS does not display; turning off Settings > Privacy & Security > Tracking > Allow Apps to Request to Track means apps cannot access it.

What an advertising ID is

An advertising ID is a long random code assigned to your phone so that apps and ad networks can recognize the same device across different apps without using its hardware serial number. Google describes the Android version as a unique, user-resettable and user-deletable ID for advertising, provided by Google Play services. Apple's equivalent is the Identifier for Advertisers, or IDFA.

The ID is useful to advertisers precisely because it is stable. If a game, a weather app and a shopping app all report the same ID, the companies receiving that data can link it into one profile. It is also one of the keys data brokers match records on: California's data broker deletion platform lists a mobile advertising ID among the optional identifiers you can add.

Android: find, reset or delete the ID

Menu names vary between Android versions and phone makers, but the screen is always called Ads. Try these paths in order:

Open Settings, tap Google, then All services, and under Privacy & security tap Ads. Google's help pages also give the shorter path Settings > Privacy > Ads, and many Samsung phones use Settings > Security and privacy > More privacy settings > Ads.
Look at the bottom of the Ads screen. Google's AdMob help confirms you can find your advertising ID in your device settings; it is shown there as a long string of letters and numbers.
To replace it, tap Reset advertising ID and confirm. A new random ID takes its place.
To switch it off, tap Delete advertising ID and confirm. No new ID is assigned.
Below the ID, open Ads privacy to manage Android's other ad features: Ad topics, App-suggested ads and Ad measurement, each with its own switch.

On very old devices running Android 4.4 or earlier, the setting is Settings > Privacy > Advanced > Ads with a switch called Opt out of Ads Personalization.

Reset or delete: which should you choose?

Choice	What happens	When it helps
Reset	The old ID is replaced by a new one. Apps start over with a fresh ID, but can still build a new profile.	You want to break the link with your past history but still see relevant ads.
Delete	The ID is removed and none is assigned. Since a 2021 Google Play services update, apps asking for it receive a string of zeros.	You do not want apps to have an advertising ID at all.

Google notes that apps can still show you ads after either choice, and that apps may have their own settings and use other types of identifiers.

If you have a Google TV, it has its own advertising ID. Google documents the same Reset and Delete options under Settings > Privacy > Ads on the TV.

iPhone: control the IDFA

iOS handles this differently. There is no screen that shows your IDFA, and no button to reset it; Google's AdMob help notes that Apple does not surface the IDFA by default. Instead, Apple's App Tracking Transparency controls whether apps may use it.

Go to Settings > Privacy & Security > Tracking.
Turn off Allow Apps to Request to Track. Apple says you will no longer get prompts, and every app that asks is treated as if you tapped Ask App Not to Track.
When asked, choose to ask all apps you previously allowed to stop tracking. You can also review apps one by one in the same list.

Apple states that when you ask an app not to track, its developer cannot access the IDFA, and may not track you using other identifying information such as your email address. Apple's developer documentation explains the technical side: the identifier an app receives is either a unique ID or all zeros, and apps get zeros without your permission.

Apple's own ads are a separate switch

Ads that Apple shows in the App Store, Apple News and Stocks are controlled elsewhere. Go to Settings > Privacy & Security > Apple Advertising and turn off Personalized Ads. Apple says this stops it using your information to target ads, though you may still see the same number of ads, based on context such as your search. The same screen has View Ad Targeting Information, which shows what Apple uses.

What limiting tracking does and does not do

Turning these settings off is worthwhile, but it is not a cloak:

You still see ads. They are less tailored, not fewer.
Apps can use other signals. Account logins, email addresses, IP addresses and data you give an app directly are separate from the advertising ID. On iPhone, Apple's rules forbid tracking with those once you have asked an app not to track; on Android, Google notes apps may use other identifiers.
Location permission is separate. An app with access to your location can still collect it. Review location access in your phone's privacy settings.
Old data stays where it is. Resetting or deleting the ID stops new links to your old profile. It does not delete records already sold. For brokers that hold those records, Californians can use DROP.

Using your advertising ID with California's DROP

California's DROP lets residents add a mobile advertising ID so brokers can match and delete records tied to it. The ID brokers have is the one your phone has used so far. So on Android, the order matters: copy the current ID from the Ads screen into your DROP profile first, then reset or delete it on the phone. iPhone users cannot read the IDFA from Settings, so that identifier is harder to submit.

Other leaks worth closing

Advertising IDs are one route. Photos you post are another: a phone picture can carry GPS coordinates and the phone model inside the file. Before you share, strip that with remove location from a photo, or check what a file contains with the EXIF viewer.

FAQ

Can I see my iPhone's advertising ID?

Not in Settings. iOS does not display the IDFA or offer a reset button. You control it through the Tracking settings instead.

Does deleting the Android advertising ID stop all ads?

No. You will still see ads, but they cannot be based on that ID. Apps may still use other information you have shared with them.

How often should I reset my advertising ID?

There is no official recommendation. If you prefer to keep an ID, resetting it now and then limits how much history builds up around one code. Deleting it avoids the question.

If I allowed an iPhone app to track me before, does turning off the main switch stop it?

Apple's developer documentation notes that an app you already authorized can keep its permission if its own switch stays on. When you turn off Allow Apps to Request to Track, choose the option to ask all previously allowed apps to stop, or check each app in the Tracking list.

Does turning off Personalized Ads on iPhone stop other apps tracking me?

No. That switch covers Apple's own ad platform. Third-party apps are controlled by the Tracking setting.

Sources

Checked 2026-10-11.

Last updated: 2026-10-11

How to find, reset or delete your phone's advertising ID