Despite its mission to challenge Big Tech dominance, Mozilla now finds itself tethered to one of its largest rivals in a paradox that could threaten the very survival of its flagship browser, Firefox.
As the Justice Department pushes forward with remedies aimed at curbing Google’s monopoly over online search, Mozilla’s financial dependence on the search giant is surfacing as a glaring vulnerability, one that the organization admits could become existential.
More: The fall of Mozilla
Mozilla’s Chief Financial Officer, Eric Muhlheim, testified in court on Friday, describing the potential fallout of the DOJ’s proposals as dire. “It’s very frightening,” he said if Google were barred from paying to remain the default search provider in Firefox.
That payment, ironically, forms the lifeblood of a browser that was created to stand as a counterweight to corporate control of the internet. Firefox generates roughly 90 percent of Mozilla’s revenue, and Muhlheim confirmed that about 85 percent of that comes from its agreement with Google; an arrangement that funds both Mozilla’s for-profit arm and, by extension, the nonprofit foundation behind it.
While the court has already determined that Google’s use of default search engine contracts amounts to illegal monopolistic behavior, Mozilla’s testimony underscores the tangled consequences of dismantling those deals. Mozilla, positioned as a David to Google’s Goliath in the browser wars, depends on the very dominance the DOJ seeks to unwind.
Muhlheim didn’t mince words about what severing the deal could mean. The immediate loss of that income would require sweeping cutbacks. He spoke of a “downward spiral” in which reduced funding for product development would degrade Firefox, prompt user attrition, and potentially “put Firefox out of business.” The ripple effects, he warned, would hit Mozilla’s other initiatives—such as its work on ethical AI and open web standards.
The contradiction is hard to miss: Firefox, hailed by digital rights advocates as a rare independent in a browser market increasingly shaped by Apple’s WebKit and Google’s Chromium, is only able to survive because of a search contract with Google. Its own browser engine, Gecko, was developed precisely to prevent a single corporation—then Microsoft—from dictating how the internet worked. Now, two decades later, Mozilla’s survival hinges on the largesse of another tech behemoth.
The DOJ’s broader vision involves creating a more competitive search landscape where multiple companies could vie for placement in browsers like Firefox, eventually replacing Google’s dominant position. But Mozilla isn’t banking on that happening soon. Muhlheim warned that even in a best-case scenario, such a transition would take years, years Mozilla may not have if its revenue stream evaporates. “We would be really struggling to stay alive,” he said.
During cross-examination, he acknowledged the downside of being overly reliant on a single partner. He also conceded that Opera, another independent browser, has managed to generate more revenue from ads than search deals, suggesting a path Mozilla could theoretically follow. But, Muhlheim argued, Firefox’s focus on user privacy complicates efforts to build a similar business model.
While Mozilla supports giving users more options when choosing a browser on new devices, a so-called “choice screen,” it resists requiring a similar interface for selecting search engines. Muhlheim said Firefox already provides multiple ways for users to pick their preferred search tool, adding, “Choice is a core value for us, but context matters…The best way to get to choice is not always a choice screen.”
Toward the end of his testimony, Judge Amit Mehta posed a hypothetical: Would Mozilla benefit from a world where another company could match Google in both quality and monetization? Muhlheim didn’t hesitate: “If we were suddenly in that world, that would be a world that would be better for Mozilla.”
Yet for now, that world remains out of reach, and the organization that once set out to break tech monopolies remains deeply entangled with one of the largest.
