You’ve googled an item once, and suddenly, every ad that appears features that exact product. A single click in one app can trigger a series of ads across other platforms, all featuring the same or similar items. While the advertising ID isn’t the sole culprit, it is one of the prime suspects—and its role in targeted, personalized ads is crucial.
Google Advertising ID (GAID) is Google’s version of the digital stick-on Post-it attached to your device that helps advertisers understand which apps you open, how much time you spend using them, and which websites you visit. Since user profiling is a major privacy concern in mobile tracking, users can now reset or delete their ad IDs. But is this strategy bulletproof?
In this article, we explore the role and relevance of the Google ad ID, opt-out options, and the privacy concerns surrounding its use.
What Is Google Advertising ID?
The Google Advertising ID (GAID) is a unique identifier code provided by Google Play Services that allows app developers to monetize their apps through user profiling and activity tracking. Also known as the Android Advertising ID (AAID), the GAID is a unique 32-character identifier assigned to each Android smartphone and tablet. This string of numbers and letters is random and contains no user-specific information.
The ID, generated separately for each device, contains 32 alphanumeric characters and four hyphens and uses lowercase letters and numerical digits, e.g.:
e4fe9bde-caa0-47b6-908d-ffba3fa184f2
Think of the GAID as a persistent tag on your device that allows apps, websites, and third-party advertisers to recognize you as a consumer across different services. Assuming one device roughly equals one user, advertisers often treat the device’s advertising ID as a proxy for a user profile.
If not disabled, apps and advertising networks may request access to this ID and use it to associate activity across apps and websites. Over time, this contributes to the development of a behavioral profile used for targeted advertising.
Note: The Google Advertising ID should not be confused with the Google Play ID. While the GAID is specifically used for campaign success monitoring, advertising, and activity tracking, Google Play identifiers are unique to Android applications and are used to manage, update, and route app files.
What Is Advertising ID Used For?
Google Advertising ID on Android is assigned to each device that installs mobile apps that utilize Google advertising services. In addition to being unique to each device, the identifier doesn’t change regardless of which apps you use or which activities you perform. That enables cross-app recognition, allowing advertisers to connect activity across different apps and services.
The three main functions of the advertising ID are:
- Behavioral tracking and user profiling: To build your advertising profile, apps and advertisers must collect sufficient valuable information about your interests and activity patterns. When you use an app, your activities within that service become part of a data profile tied to your advertising ID. As long as the ID is active, apps and third-party advertisers can request access to this information and use click data, engagement signals, and habit patterns to build a behavioral profile.
- Ad personalization: Based on data collected through tracking, advertisers or data broker networks can create a fairly specific picture of your interests. At this stage, ads are tailored based on the intent signals the ID has “caught.” That is when you see highly targeted ads, recommendations, or retargeting attempts based on products and services you’ve previously interacted with.
- Campaign performance measurement: Through device-level attribution, GAID can signal to advertising systems whether an ad interaction led to a desired outcome, such as completing a subscription, purchasing a product, or installing an advertised app. That allows advertisers to measure campaign effectiveness and identify which ads drive conversions.
How Does Google Advertising ID Tracking Work?
The following table outlines the key components in the user tracking and profiling mechanism, and the role of GAID in their functioning:
Component | Details | GAID Role |
Mobile apps and websites | Primary tracking and data collecting surface where users interact with content and ads | GAID is accessed when users interact with apps and/or in-app content |
Software development kits (SDKs) | Set of pre-built tools (e.g., documentation, code libraries) embedded in the platform, storing user activity data and sending it to advertising networks | GAID is attached to specific user actions, such as clicks, installs, subscriptions, and purchases |
Mobile measurement partners (MMPs) | Third-party attribution providers that collect data across different devices and surfaces and track campaign engagement | GAID is used to collect activity data and match user interactions with conversions |
Demand-side platforms (DSPs) | Software through which advertisers purchase digital ad space on websites and apps | GAID-based signals help build audience categories and determine which ads to bid on and display |
Is Google’s Privacy Sandbox Replacing GAID?
While there have been discussions about Google moving away from traditional attribution and cross-app tracking methods, GAID remains an active element in the advertising ecosystem and is still widely used by advertisers.
Instead of relying solely on a single device-level identifier like GAID, Privacy Sandbox was designed to group users into broader interest categories rather than track their specific actions. The ultimate goal was to reduce cross-site and cross-app tracking and protect sensitive user-identifying information by running key advertising processes locally on the device.
For example, rather than tracking a specific action, such as user X searching for Y, Privacy Sandbox technologies were intended to place users into broader interest groups, such as fitness, food, or travel. This way, advertisers could still assess general-interest signals relying as heavily on user profiling and persistent identifiers.
Today, this initiative, introduced as a more privacy-conscious alternative to persistent identifiers and cross-app tracking, is largely fragmented and deprecated. Following pushback from advertisers and broader industry feedback, Google has retired or reworked many of its Privacy Sandbox components.
As of now, it is still unclear how the privacy-focused initiative will evolve in the long term.
How To Find Advertising ID on Android
On your Android device, you can easily find the advertising ID and related settings by following these steps:
- Open your phone’s Settings
- Tap Privacy
- Select Ads
On some older versions of Android, the pathway may differ slightly:
- Open Settings
- Tap Privacy
- Select Advanced
- Tap Ads
Inside the Ads menu, you may see the following options:
- Reset Advertising ID
- Delete Advertising ID
- Opt out of Ads Personalization (on some older versions of Android)
What Does Resetting Advertising ID Do?
When you reset your advertising ID, your current advertising profile ceases to exist and is effectively disconnected from future activity on the device. Once reset, new app activity and interactions can no longer be directly linked to the previous identifier, and a new ID is created.
In practice, this means that you’re essentially reprogramming the advertising system to “forget” your old habits and gradually rebuild recommendations and ads based on new activity patterns.
The main difference between resetting and deleting your advertising ID is that resetting replaces the old ID with a brand-new one, meaning apps can still deliver personalized ads. For a while, until enough new behavioral data is collected, these ads may feel less relevant or less accurately targeted.
However, resetting your GAID doesn’t necessarily mean that old profiling data vanishes. Even Google notes that apps may rely on their proprietary identifiers or additional tracking methods that may linger even after you’ve reset the ID.
As a result, you may still encounter personalized ads based on past activities, though after a reset, they are generally attributed to other tracking methods rather than the previous GAID.
What Does Deleting Advertising ID Do?
Deleting your advertising ID disables the identifier, and no new ID is created in its place. When you opt out, apps or advertisers attempting to access the ID receive a string of zeros instead of the unique alphanumeric code. Therefore, it is fair to say that deleting your GAID is a more permanent way to break the direct link between your activity and your advertising ID.
Still, many of the same tracking techniques that exist when you reset your ID can also apply in the case of deletion. Deleting your advertising ID may dissolve the connection between your mobile activity and the identifier itself, but it doesn’t eliminate alternative tracking methods used across apps and advertising systems.
How Google Ad ID Compromises User Privacy
In some cases, GAID may be portrayed as a benefit because it personalizes ads and ensures you see those that align with your activities and interests. However, the mechanism by which apps and advertisers achieve this level of personalization is, in essence, a trade-off that affects user privacy.
The user profiling system based on GAID relies on user tracking across different apps and services. This surveillance-style method ensures that the user isn’t safe from its prying eye in any corner of the mobile experience.
While resetting or deleting GAID temporarily or permanently breaks the link between your activity and identifier, tracking may persist through proprietary identifiers used by apps. Additionally, the advertising ID is only one piece of the broader tracking puzzle, alongside third-party cookies, IP address-based data, and network-level threats.
User privacy depends not only on app-level controls but also on the network infrastructure and its vulnerabilities. While app-related threats focus on profiling and advertising behavior, the network level introduces a different category of risk. Potential risks stemming from network-based data leaks or breaches include account takeover, SIM swapping, and interception.
Choosing a privacy-focused mobile carrier like Cape minimizes the amount of sensitive data stored and processed at the network level, limiting the risk of data exposure and misuse. In doing so, it addresses a more sensitive privacy concern that exists beyond app-level tracking, protecting against large-scale threats tied to the mobile infrastructure itself.
Cape: The Carrier Built for Security and Privacy
Cape is a privacy-first mobile carrier designed to keep your communications safe from surveillance and misuse. Unlike traditional cell phone plan providers, our business model centers around providing you with premium and secure call, text, and data, rather than harvesting and selling your information.
Our service is built from the ground up with privacy and security at its core, offering unique features like:
Privacy & Security Feature | Description |
Cape doesn’t ask for your name, address, or Social Security number. We only collect the information necessary to provide service, and we retain that information for the minimum amount of time possible. | |
Traditional carriers rely on a fixed International Mobile Subscriber ID (IMSI) to connect your device to cellular networks. This is a vulnerability that lets carriers, advertisers, and bad actors identify and track your device. Cape lets subscribers automatically rotate their IMSI every 24 hours, making it infinitely more difficult to track you or your device. | |
Many services ask for your phone number, but sharing it exposes you to spam, scammers, data brokers, and a variety of other risks. VoIPs, on the other hand, don’t work with 2FA, cost extra, and aren’t encrypted. With Cape, you get two free additional SMS/MMS lines that are middle-to-end encrypted. | |
Most U.S. carriers store your call and text metadata for years, sometimes indefinitely. Cape is built to forget, so call data records (CDRs) are deleted after just 24 hours. | |
Cape nullifies the threat of SIM swapping by completely removing humans from the loop. During signup, you receive a 24-word phrase that generates a private key tied to your number. This effectively means that no one (but you) can move your number to a new carrier or device, not even Cape. | |
Legacy network protocols, like SS7, leave you vulnerable to hackers that can track your location, intercept your calls and texts, and steal sensitive information. Cape’s Network Lock relies on a proprietary signaling proxy to verify that your device’s physical location matches the network it’s trying to attach to. If we detect anything out of the ordinary, Cape automatically blocks the connection, nullifying the potential threat. | |
Traditional voicemail systems are outdated, unencrypted, and another security hole bad actors can exploit to gain access to your sensitive information. Cape encrypts all voicemails, ensuring only you can access them. | |
While roaming, your phone connects to local telecom providers to enable service. But, who knows who might be listening on the other end. Cape provides you with peace of mind by routing your traffic through our U.S.-based mobile core, ensuring your identity, data, and communications remain private and secure. |
Ditch Legacy Carriers: Get Cape Today
Cape is a “Heavy” Mobile Virtual Network Operator (MVNO), meaning we own our mobile core and provision our own SIMs. This gives us full control over how accounts are authenticated and what data is collected (and for how long), and is how we are able to provide privacy and security features no other carrier on the market can offer.
Get started with Cape today and enjoy the peace of mind, knowing you are fully protected against scammers, hackers, bad actors, and other mobile threats.
To help protect more than just your phone, we’ve partnered with Proton. As a new Cape subscriber, you can choose between Proton Unlimited and Proton VPN Plus for just $1 for six months.
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