Mozilla Firefox could be collateral damage in Google’s antitrust battle

Mozilla, the creator of Firefox browser, has issued a dire warning that remedies aimed at curbing Google’s search monopoly could inadvertently kill one of the few remaining independent forces in web browsing.

The stark assessment came as Mozilla CFO Eric Muhlheim testified in Google’s defense against Department of Justice antitrust proposals, calling the potential outcomes “very frightening” for the browser’s future, the Verge reported.

The DOJ wants to bar Google from paying to be the default search engine in third-party browsers like Firefox.

“Banning default search placement deals may weaken Google’s grip, but it risks crippling the very alternatives meant to provide choice,” said Sanchit Vir Gogia, CEO and chief analyst at Greyhound Research. “The remedy must distinguish between dominant gatekeepers and dependent participants.”

Financial dependency creates unexpected vulnerability

In a court testimony on Friday, Muhlheim revealed the extent of Mozilla’s financial dependence on Google, painting a picture of an organization caught in a precarious position. According to the report, Muhlheim disclosed that Firefox generates approximately 90% of Mozilla’s total revenue, with about 85% of that revenue coming directly from Google.

The search giant pays Mozilla substantial fees to remain the default search engine in Firefox, creating a revenue stream that Mozilla argues is essential to its survival. Court documents and testimony show that in 2023, Mozilla generated approximately $495 million from such licensing arrangements out of $653 million in total revenue.

“Losing that revenue all at once would mean Mozilla would have to make significant cuts across the company,” Muhlheim testified, describing a potential “downward spiral” where reduced investment in product engineering would make Firefox less attractive to users, ultimately threatening its existence.

DOJ proposals vs browser diversity

While the DOJ has successfully argued that Google maintains an illegal monopoly in search partly through exclusionary default agreements with browsers and phone manufacturers, Mozilla contends that abruptly ending these arrangements could have catastrophic unintended consequences.

The court is considering a range of remedies, including barring Google from paying to be the default search engine in third-party browsers like Firefox, potentially forcing a sale of Chrome, and requiring Google to syndicate search results to competitors.

What makes this situation particularly ironic is that Mozilla’s collapse could actually reinforce the market concentration that the antitrust case aims to dismantle. Muhlheim emphasized that Firefox’s underlying Gecko browser engine is “the only browser engine competing with Google’s Chromium and Apple’s WebKit,” Mozilla wrote in a blog post.

Limited alternatives for Mozilla

Mozilla has explored alternatives to Google funding but found them wanting. According to court documents detailed by the report, Mozilla has discussed the possibility of making Microsoft’s Bing the default search engine, but Muhlheim warned that without Google being able to bid on the contract, the revenue share Mozilla could negotiate would likely plummet.

A December 2024 presentation to Mozilla’s board, shown in court, characterized losing Google’s payments as a “significant threat to viability for Mozilla with limited ability to mitigate.”

The organization has historical evidence for its concerns. Between 2014 and 2017, Mozilla made Yahoo the default search engine in Firefox, but “found that people disliked the experience so much that they switched to another browser altogether,” Mozilla said in the blog post.

While the DOJ argued that its proposals would eventually create multiple quality search engines that could compete for Firefox’s default position and replace Google’s revenue share, Mozilla contended that this transformation would take too long for the organization to survive the transition.

“We would be really struggling to stay alive,” Muhlheim testified, explaining that Mozilla would face significant cost cuts and strategy changes while “waiting on a hypothetical future” where competitive search alternatives materialize.

Seeking new revenue streams

Under cross-examination by the DOJ, Muhlheim conceded that relying on a single customer for the vast majority of revenue is problematic, regardless of the court’s ruling. He acknowledged that another browser company, Opera, has already managed to generate more revenue from browser advertisements than from search deals.

However, Muhlheim suggested that such a pivot might be more challenging for Firefox given its strong commitment to user privacy — a core differentiator in the market, the report added.

Mozilla has begun diversifying its business operations, expanding into artificial intelligence and digital advertising to secure Firefox funding for the future. Recent changes to Firefox’s terms of use regarding user data handling suggest strategic adjustments as the organization navigates these challenging waters.

Implications for web standards

Industry analysts warn that Firefox’s potential demise represents more than just the loss of a popular browser.

“If Firefox were to shut down, it wouldn’t just mark the death of a browser — it would mark the end of one of the last surviving independent rendering engines, Gecko,” said Gogia of Greyhound Research.

As this high-stakes antitrust battle continues to unfold, the technology industry is watching closely to see whether regulatory efforts to restore competition will succeed in fostering a healthier digital ecosystem or inadvertently eliminate one of the few remaining independent voices in browser development. “This case will shape the competitive landscape of the internet for years to come, and any remedy must strengthen, rather than weaken, the independent alternatives that people rely on for privacy, innovation, and choice,” Laura Chambers, CEO of Mozilla, wrote in the blog post.