The Ethereum Foundation, including researcher Vitalik Buterin, has unveiled a long-term roadmap to transition the network to 'Lean Ethereum' by the end of 2029. The strategy involves a sequence of approximately seven hard forks designed to overhaul the protocol's consensus, execution, and data layers while maintaining backward compatibility for existing applications.
The upgrade sequence, labeled from H* to L*, includes two key upcoming forks: Glamsterdam and Hegotá. The latter is expected to occur in late 2026 or early 2027. The final L* fork will mark the completion of the Lean Ethereum transition. The roadmap was initially proposed by Justin Drake in mid-2025 and further clarified in November 2026.
A central focus of the plan is implementing quantum-safe, hash-based signatures to mitigate risks from future quantum computing developments, which are anticipated around 2030. Additionally, the network will integrate recursive STARK proofs to verify transaction batches more efficiently by allowing proofs to verify other proofs.
The transition introduces a two-tier state model. The project estimates that tokens utilizing the new scalable tier could see transaction fee reductions of more than 10x. Researchers emphasize that community adoption of the initial Glamsterdam and Hegotá forks will serve as a critical indicator for the success of the broader strategic roadmap.
