Horizon3 AI

Horizon3 AI, founded in 2019, is a cybersecurity company that builds an autonomous penetration testing platform designed to help organisations find, fix and verify exploitable attack vectors before attackers can reach them. Its flagship product, NodeZero™, runs production-safe autonomous pentests and provides continuous security validation at scale, assessing security posture across internal, external, cloud and hybrid environments. The company is present in North America and serves customers globally.

NodeZero™ is used by organisations ranging from small educational institutions to Global 100 enterprises and government agencies. Its customer base spans the education and public sectors, enterprise IT, IT operations and SecOps teams, consulting penetration testers, and managed security service providers. In the Deloitte Fast 500 for 2025, the company ranked as the third fastest-growing in North America.

The company's technical work covers autonomous penetration testing, attack surface assessment, cloud security, continuous security validation and hybrid environment security. Its stated focus includes addressing ineffective security tooling, false positives, alert fatigue and the shortage of skilled cybersecurity practitioners. The team includes former U.S. Special Operations cyber operators, startup engineers and cybersecurity practitioners.