Ads performance, re-imagined. Now in beta: Anonym Private Audiences.

Together, Mozilla and Anonym are proving that effective advertising doesn't have to come at the cost of user privacy. It's possible to deliver both - and we're building the tools to show the industry how.

Today, we're unveiling Anonym Private Audiences: a confidential computing solution allowing advertisers to securely build new audiences and boost campaign results.

Powered by advanced privacy-preserving machine learning, Anonym Private Audiences enables advertisers and platforms to work together using first-party data to create targeted audiences without ever handing their users' information to one another. Brands can discover and engage look-alike communities - reaching new high value customers - without sending, or exposing their customers' data to ad platforms. As the evolving advertising landscape makes third-party data less viable, Private Audiences supports privacy while enabling the performance advertisers have come to expect.

Private Audiences employs differential privacy and secure computation to minimize the sharing of data commonly passed between advertisers and ad networks. It operates separately, and is not integrated with, our flagship Firefox browser.

Why advertisers are turning to Private Audiences

Advertisers today are facing a difficult challenge: how to grow their business without breaking the trust of the people they're trying to reach. Private Audiences was built to meet that moment - helping teams use the data they already have to find new high-value customers, without giving up data control along the way.

Early adopters are already seeing meaningful gains, with campaign performance improving anaverage of 30%compared to traditional broad targeting. And the reasons why it's resonating are relevant to any brand looking to grow smarter and more sustainably:

• Find the right people, not just more people. Predictive machine learning helps advertisers reach new audiences that look and behave like their best customers - improving efficiency without ramping up spend.

• Keep trust intact. In sectors where privacy expectations are highest, early adopters are showing that it's possible to respect user's privacy and still drive results.

• Use what you already know. Private Audiences works with the tools teams already rely on. Audiences show up in platform-native interfaces, so there's nothing new to learn or configure.

• Stay ahead of shifting standards. Private Audiences is built on privacy-first architecture - helping brands keep pace with evolving norms, expectations, and technical requirements.

How Private Audiences protects user privacy

In most audience-building workflows today, advertisers integrate directly with ad platforms to share customer data- whether through raw file uploads or automated server-to-server transfers. The platform then uses that data to build look-alike' audiences or, in some cases, retarget those same individuals directly. Anonym's approach enables businesses to retain full control over their user data and employ gold standard protections, which are particularly important in privacy-sensitive industries and regions.

Private Audiences takes a fundamentally different approach

Instead of sharing data directly with platforms, brands securely upload a list of high-value customers using a simple drag-and-drop interface. That data is encrypted and processed inside Anonym's Trusted Execution Environment (TEE), where audience modeling happens in isolation. No data is exposed - not to Anonym, and not to the platform. Anonym trains the model, ranks eligible audiences based on likely performance, and returns a ready-to-use audience segment. Anonym's ad platform partners only learn which of their existing users to include in the audience - they receive no new personal information or audience attributes. When the process is finished, the TEE is wiped clean.

The result: strong performance, without giving up data control or compromising on privacy.

Breakthrough performance and privacy capabilities with Private Audiences, and more

Private Audiences joins the ranks of Anonym's other solutions: Private Attribution, which enables accurate view-through attribution without user tracking, and Private Lift, which helps advertisers understand incrementality without exposing identities. Together, Anonym's tools represent a new foundation for digital advertising trust - a solution portfolio built on transparency, accountability, and respect for the people it reaches.

Because trust isn't optional - it's foundational

Mozilla has always believed privacy is a fundamental human right, and we will continue our relentless focus on designing and delivering products and services to protect it. Advertising performance -as much as privacy -is a foundational part of this journey.

Anonym Private Audiences is currently in closed beta, supporting early-use cases where privacy matters most. We're excited to partner with all advertisers seeking a better way to build high-performing audiences without compromising your customers' trust.

For a deeper dive or beta participation details, get in touch with us here.

Performance, powered by privacy Learn more about Anonym

The post Ads performance, re-imagined. Now in beta: Anonym Private Audiences. appeared first on The Mozilla Blog.