Read the Portuguese version here.
Competition is a strength of the internet. When people freely choose among browsers, search engines, and apps, companies compete on merit. However, digital markets have concentrated around ‘gatekeepers’ that control discovery, making it harder for independent developers to reach users. Traditional enforcement has proven ineffective, often arriving too late. Governments worldwide are now adopting new tools to ensure open, contestable markets.
Brazil’s Bill 4,675/2025 is a critical step in this direction. Drawing lessons from the EU’s Digital Markets Act and the UK’s Digital Markets, Competition and Consumers regime, the bill addresses structural competition concerns with an approach calibrated to Brazil’s market realities. Mozilla strongly supports this legislation, which aims to establish a tailored competition framework for Brazil’s digital markets.
Competition unlocks better products and meaningful choice
For over twenty years, Mozilla has built Firefox as an independent browser prioritizing privacy, security, and choice. We operate on Gecko, one of only three browser engines worldwide. Maintaining independence is critical to preventing market dominance and ensuring users have genuine choices. Innovation alone isn’t enough; products need fair opportunities to compete without being hindered by preinstallation or interoperability barriers.
Bill 4,675 addresses this via an ex ante framework, allowing Brazil’s competition authority to mitigate risks before they become irreversible. The latest draft improves this framework in several important ways. It tailors obligations to specific products and services rather than automatically applying them across an entire corporate group, strengthens procedural safeguards throughout the designation process, and places clearer limits on the authority’s ability to expand obligations beyond those established in legislation. Most notably, it requires “neutral and non-discriminatory” choice architecture, including choice screens, for selecting, installing, or setting third-party products as defaults.
Mozilla’s experience with browser choice screens under the EU Digital Markets Act proves these provisions work. Firefox has been selected more than six million times, and users who select Firefox through these screens are five times more likely to continue using it. By making the framework targeted and predictable, Bill 4,675 establishes a foundation for a competitive ecosystem where innovation drives success.
How competition delivers for people
Competition policy is about people. Open markets provide genuine choice and allow smaller players to thrive. Critics argue these proposals harm innovation, but our experience suggests the opposite. Gecko, Firefox’s browser engine, remains the only major independent engine not controlled by a dominant OS operator. This independence enables us to prioritize user-focused innovations like advanced privacy and security protections.
Design decisions, like preinstalled defaults and interoperability barriers, significantly shape the user experience. Mozilla’s Over the Edge 2.0 research highlights how these practices undermine choice. Startups similarly benefit when they can reach users and compete on merit rather than relying on dominant platform decisions. Brazil’s bill can foster these conditions by providing CADE with tools to address anti-competitive practices, ensuring dominant platforms compete by improving product quality rather than leveraging infrastructure control.
Looking ahead
Digital markets evolve, but healthy competition principles—openness, choice, interoperability, and transparency—remain constant. Bill 4,675 translates these into enforceable rules. Its tailored ex ante model and procedural safeguards position Brazil among jurisdictions restoring market balance. Ultimately, the framework’s success will be measured by its ability to deliver meaningful change for users.
Mozilla supports this bill and looks forward to collaborating with lawmakers, CADE, and stakeholders. With targeted refinements, Bill 4,675 can become a durable framework that promotes competition, supports innovation, and empowers people with greater choice.