Island, a Dallas company that makes an enterprise web browser with built-in security controls, raised $400m in a Series F round on 24 September 2026 at a valuation of $6.4bn. Evolution Equity Partners led the round.
Existing investors Prysm Capital, Sequoia Capital, Coatue Management, Cyberstarts, Insight Partners, J.P. Morgan Growth Equity Partners, Alta Park Capital, Georgian, G Squared and Squarepoint also took part, along with cybersecurity entrepreneur Dmitri Alperovitch, who invested personally. Island said the valuation had more than doubled since 2024.
The company said the money would fund its next phase of growth and product development as enterprises scale their use of AI agents. DigitalToday, citing SiliconANGLE, reported that Island plans to use the funds for product development and market expansion and to hire 500 people by mid-2027.
“We’ve entered a new era in which people and AI agents work side by side. Just like humans, agents need the right context, access, guardrails, and accountability to succeed.”Mike Fey, CEO and Co-founder, Island
What Island does
Island built a Chromium-based browser for corporate use that embeds security, access and productivity controls into the place where most office work happens. Users who prefer consumer browsers can get the same controls through an extension. The company has since added data loss prevention, endpoint software and a network product that it describes as a next-generation SASE architecture built from the endpoint outward.
Island now describes itself as an agentic control plane: one policy engine and one audit trail covering browsers, endpoints, applications, networks and data, for both human staff and AI agents. Its Enterprise AI product covers identity governance, access, guardrails, data boundaries, human approvals and cost controls for AI tools and agents.
Co-founder and chief technology officer Dan Amiga said agents do not operate in a single layer of the technology stack and so cannot be governed from one.
Growth and customers
Island said it employs 1,000 people and has doubled annual recurring revenue every fiscal year since its launch in 2022. It did not give a revenue figure in its announcement; Crypto Briefing reported annual recurring revenue of about $200m as of September 2026.
Crypto Briefing also reported that Island's clients include eight of the world's ten largest banks, along with Citi, Pfizer and T-Mobile, and that it has more than 700 enterprise clients. The company said millions of users rely on its products.
Gili Raanan, founder and general partner of Cyberstarts, which backed Island at its start, said reaching a $6.4bn valuation while doubling ARR each year showed the company had built something enterprises needed.
The company also listed recent recognition, including a place on the 2026 CNBC Disruptor 50 list and a Customers' Choice designation in Gartner's 2026 Peer Insights report on secure enterprise browsers.
The funding so far
The Series F follows a $250m Series E in March 2025, led by Coatue Management, which valued Island at $4.8bn. At the time Island said it had raised about $730m in outside investment. SecurityWeek reported that the new round takes total investment in the company to well over $1bn.
Island was co-founded by chief executive Mike Fey and Amiga. SecurityWeek and Crypto Briefing date the company's start to 2020.
Company website: island.io