Google is going to start blocking cross-app tracking on Android in a multi-year effort to replace the existing online advertising system for its mobile OS with a privacy-preserving alternative.

The company mentioned the news on Wednesday as part of an announcement about new privacy-focused restrictions that will stop Android apps from profiling users’ internet activities.

“​​Specifically, these solutions will limit sharing of user data with third parties and operate without cross-app identifiers, including advertising ID. We’re also exploring technologies that reduce the potential for covert data collection,” Google said. This includes stopping advertisers from using other forms of data to fingerprint users. 

The announcement arrives a year after Apple introduced privacy controls for iOS that, among other things, required iOS software developers to first ask users for permission to track their activities across both the web and third-party apps in order to serve tailored ads.

Google's Wednesday statement signals the tech giant is preparing to cut out cross-app tracking too. Android currently makes cross-app tracking easy by giving each device an advertising ID, which software developers can collect to determine which apps you’ve been using.

To avoid the tracking, users can manually reset an advertising ID or even opt out of the ad system by going into the Android OS settings. However, third-party apps can still collect other kinds of data, such as a phone’s serial number or IP address, to fingerprint a user and track them across the internet. 

In response, Google is working on a new system for Android that promises to prevent user tracking without disrupting the online advertising industry. The effort is called the Privacy Sandbox for Android and it builds on Google’s existing efforts to phase out cookie-based advertising on the Chrome browser for a privacy-focused advertising system. 

Don’t expect Google to follow in Apple’s footsteps, though. The company’s announcement takes some a shot at Apple by linking to a study that claims iOS's App Tracking Transparency system only provides the illusion of privacy protections when many third-party apps can still collect plenty of user data. 

“We believe that — without first providing a privacy-preserving alternative path — such approaches can be ineffective and lead to worse outcomes for user privacy and developer businesses,” Google added. (Other companies such as Facebook say the iOS privacy changes are a huge financial drain on their advertising models.) 

Google's alternative is to first create new ways to serve targeted ads for the industry before the company begins phasing out the advertiser ID system and blocking the covert forms of tracking. 

One of the proposals is called Topics API, which Google is already planning to implement for the Chrome browser. Topics API essentially works by using on-device processing to determine a handful of topics you’re interested in based on your web history, and then feeding a random one to advertising networks.  

Another proposal from Google is called FLEDGE, and it also involves on-device processing to store information on what apps your Android device has recently accessed. Advertising networks can then get your phone to display ads related to the apps you’ve used. 

Google created a dedicated website about the proposals, which will arrive later this year through previews for Android developers. A beta release is scheduled to be launched by year's end.

Google added: “We’ve offered public commitments for our Privacy Sandbox efforts on the web, including ensuring that we don’t give preferential treatment to Google's ads products or sites. We'll apply these principles to our Android work as well.” 

In the meantime, the company plans on supporting its existing advertising systems for Android for at least two years.