Lean Ethereum is expected to span roughly three to four years and replace nearly all of the protocol’s core components, including validation mechanisms, data storage, the virtual machine, privacy architecture and future quantum-resistance capabilities.
Vitalik said this phase will involve replacing almost every critical part of Ethereum while ensuring that existing applications can continue operating without modification, similar to how the network successfully transitioned from Proof-of-Work to Proof-of-Stake during The Merge.
The new roadmap was announced after a meeting of Ethereum researchers in Berlin at the end of June and updates the Strawmap framework introduced by Justin Drake earlier this year. The roadmap now includes seven hard forks planned through 2029, with goals such as reducing transaction finality to just a few seconds, significantly increasing Layer-1 and Layer-2 throughput, integrating post-quantum cryptography and making privacy a native protocol feature.
Vitalik also stated that Hegota, the second upgrade expected in 2026, will likely be the final hard fork of the pre-Lean era.
Transaction Fees Could Fall More Than Tenfold
According to Vitalik Buterin, the most significant change in Lean Ethereum concerns how the blockchain stores state.
At present, Ethereum maintains data such as wallet balances, smart contracts and DeFi states within a unified storage structure that is expensive to operate. Lean Ethereum would introduce a new, lower-cost storage layer for mainstream applications, while the current system would continue serving more complex smart contracts.
If successful, Ethereum could hold around 2 TB of traditional state data and more than 100 TB of data in the new storage layer by 2030, allowing the blockchain to scale without meaningfully increasing operating costs.
Vitalik said that most ERC-20 tokens, NFTs and standard DeFi applications could migrate to the new storage layer, while more complex protocols such as Uniswap would likely remain on the existing architecture. Migration would be entirely voluntary, but could be highly cost-efficient, with the potential to reduce transaction fees by more than ten times for applications redesigned around the new model.
At the same time, Ethereum continues to pursue a long-term plan to replace the Ethereum Virtual Machine (EVM) with a new architecture such as RISC-V or leanISA. Ethereum’s co-founder argues that a more efficient virtual machine could make cryptographic proof generation significantly cheaper, opening the door for broader zk-proof applications and privacy features integrated directly into the blockchain.
The proposal remains controversial within the developer community. Previously, the Arbitrum development team argued that WebAssembly (WASM) would be a better alternative to replace the EVM.
Quantum Resistance and Privacy Become Top Priorities
One of the most notable changes in the new roadmap is that quantum security has been elevated to the highest priority level.
Vitalik warned that once sufficiently powerful quantum computers emerge, they could break the cryptographic algorithms that currently protect most blockchains. Ethereum therefore aims to replace all vulnerable components before that risk becomes material.
The most urgent priority is the development of quantum-resistant blob mechanisms. Blobs are a temporary data layer that plays a central role in helping Layer-2 networks reduce transaction costs. Without adequate protection, Ethereum’s entire scaling ecosystem could face future vulnerabilities. Research has been underway for several months and is now being accelerated.
Privacy has also been formally identified as a core protocol objective rather than an optional feature provided through third-party applications. Future Ethereum features are expected to include user-data protection from the design stage, continuing the direction Vitalik has pursued through the Kohaku wallet project and earlier private-transaction initiatives. Privacy is now one of the five “North Stars” of Strawmap, alongside scalability, processing speed and post-quantum security.
Lean Ethereum was announced only days after the Ethereum Foundation completed its largest restructuring in years, cutting 54 employees, or around 20% of its workforce, in an effort to streamline operations and focus resources on strategic priorities.
The Ethereum Foundation has also seen several leadership changes. Some members of the community have expressed concerns that funding for core-development teams could gradually decline unless a more sustainable financing model is found. Former Ethereum engineer Dankrad Feist previously proposed creating a $1 billion organisation to support long-term development, communications and ecosystem expansion.
At the same time, the private sector is playing an increasingly important role in supporting Ethereum. EthLabs, a non-profit research organisation co-founded by five former senior Ethereum Foundation researchers, recently launched with funding from two prominent ETH treasury firms, Bitmine and SharpLink. The organisation will focus on areas aligned with Lean Ethereum, including scalability, faster processing, interoperability, security and infrastructure for tokenised real-world assets, stablecoins and DeFi.
Shortly afterwards, Bitmine and SharpLink also supported the creation of Ethereum Institutional, another non-profit organisation aimed at bringing Ethereum closer to financial institutions and Wall Street capital.
ETH is currently trading near $1,781, up more than 1.2% over the past 24 hours, as investors continue to assess the long-term implications of Ethereum’s most ambitious transformation since The Merge.
Conclusion:
Lean Ethereum is one of the network’s most ambitious technical plans since The Merge, but its success will depend on execution, developer adoption and whether the ecosystem can coordinate around major protocol changes without disrupting existing applications. If implemented effectively, it could strengthen Ethereum’s position in DeFi, tokenized assets, stablecoins and institutional blockchain infrastructure.
