Island, the enterprise browser company that has repositioned itself as a governance layer for AI agents inside corporations, has raised $400 million in a Series F round that values the company at $6.4 billion, more than double its valuation from an earlier round in March 2025.
The round was led by Evolution Equity Partners, with participation from existing backers including Sequoia Capital, Coatue Management, Insight Partners and J.P. Morgan Growth Equity Partners, alongside newer investors such as Prysm Capital, Cyberstarts, Alta Park Capital, Georgian, G Squared and Squarepoint, plus a personal investment from CrowdStrike co-founder Dmitri Alperovitch. The raise brings Island's total funding to more than $900 million.
From browser security to agent governance
Island launched in 2022 with an enterprise browser meant to replace consumer tools like Chrome inside corporate environments, giving IT departments control over what data employees could copy, paste or upload. The company says it has since expanded that same control layer to cover AI agents acting on employees' behalf, arguing that the browser is where organizations can most reliably see and govern the intersection of human workers, automated agents and sensitive data. Chief executive Mike Fey described the pitch as extending a security model built for people to the software agents now operating inside enterprise systems.
The browser is the only place where you can govern the intersection of humans, agents, and data at scale.
Mike Fey, CEO, Island
The company says it now employs roughly 1,000 people, serves millions of users, and has doubled its annual recurring revenue every fiscal year since launch, though it has not disclosed specific revenue figures. Island has also picked up industry recognition this year, including a spot on CNBC's Disruptor 50 list and Frost & Sullivan's designation as its Zero Trust Browser Security Company of the Year.
A crowded race to govern AI agents
Island's bet is that enterprises will manage AI agents the same way they manage employees: through a single control point rather than a patchwork of tools. That view puts it in competition with a growing set of rivals pursuing different architectures for the same problem, including vendors that monitor agent activity at the application-programming-interface level and others that route agent traffic through dedicated cloud environments. Investors' willingness to more than double Island's valuation in under two years suggests some conviction that browser-based control will be one of the winning approaches as companies move from experimenting with AI agents to deploying them at scale, though the enterprise security market has historically supported multiple competing architectures rather than a single standard.
Island said the new funding will go toward expanding its Enterprise AI and Enterprise Network products and scaling internationally, without specifying a timeline for an initial public offering or further fundraising.
