Prominent startup accelerator Y Combinator has filed a sharp amicus brief in the landmark U.S. antitrust case against Google, accusing the tech giant of being a monopolist whose market dominance has severely harmed the startup ecosystem.
In the filing submitted on May 9, Y Combinator argued that Google’s monopolistic hold over web search and digital advertising markets has created a “kill zone,” thereby strongly discouraging venture capital firms—including Y Combinator itself—from backing promising web search and AI startups. “Google has chilled independent firms like Y Combinator from funding and accelerating innovative startups that could otherwise have challenged Google’s dominance,” the accelerator declared, adding that this has resulted in an “artificially stunted and stagnant” competitive landscape for American technology companies.
Specifically, Y Combinator said it is actively seeking emerging technology startups capable of revolutionizing the way people interact with online information through question-driven and agentic artificial intelligence tools. However, the accelerator expressed clear concerns that Google’s market position gives it incentive and capability to disrupt these potential innovations. “Google has effectively frozen the web search and text advertising markets for over a decade,” Y Combinator stated in its brief.
Despite its hard-line accusations, Y Combinator made clear that it does not advocate immediately breaking up Google. Instead, it recommends the court mandate certain changes aimed at reducing anti-competitive practices. Among the proposed adjustments is requiring Google to cease paying billions of dollars to Apple in exchange for being the exclusive default search engine on iPhones. Even more notably, Y Combinator proposed compelling Google to make its search index accessible to external companies, enabling competitors’ large language models (LLMs) to utilize that data. Such a demand marks an extraordinary step, equating roughly to requiring Microsoft to open-source its Windows operating system or forcing Amazon to provide delivery infrastructure to competitive firms without charge.
Should Google fail to implement these suggestions within five years, however, Y Combinator recommends even more aggressive action—a forced divestiture or spin-off of key business units. Garry Tan, CEO of Y Combinator, described this scenario as the threat of a “spinoff hammer,” emphasizing via social media that while the incubator appreciates Google’s leadership in U.S. technology innovation, it also strongly supports the interests of smaller tech companies and innovators entering the field.
This move comes after significant legal setbacks for Google: The company lost a major antitrust case last year centered on monopolistic practices in search markets. The U.S. government, now considering potential remedies against the tech giant, is set to deliver its recommendations by August 2025. Among the remedies under consideration, for example, might be requiring Google to spin off its Chrome browser.
Notably, Y Combinator’s criticism contrasts sharply with its past partnerships and collaborations with Google. Y Combinator startups benefited recently from Google Cloud’s provision of Nvidia GPU clusters, and Google co-founder Larry Page notably made a rare public appearance at a Y Combinator event late last year. Additionally, Google previously acquired two Y Combinator-backed startups (Flutter in 2014 and Fridge in 2011), and invested in another Y Combinator alumnus, Infisical. Such relationships underline the complexity—and perhaps the audacity—of Y Combinator’s current stance.
Meanwhile, speculation emerged from venture capitalist Sheel Mohnot that OpenAI—a direct Google competitor whose current CEO Sam Altman formerly led Y Combinator—stands to benefit prominently if the regulators adopt YC’s recommended actions. Mohnot further implied that the brief exaggerates Google’s market strength.
So far neither Y Combinator nor Google has provided specific responses regarding these broader implications. Google, however, previously responded through public statements to similar government remedies proposals, calling them “radical and sweeping” and arguing that they would ultimately harm consumers, businesses, and developers alike.
