Vitalik Buterin Says ‘Lean Ethereum’ Will Reshape the Network Over Next Four Years

Highlights:

• Vitalik Buterin says Lean Ethereum will reshape the network through several upgrades over four years.
• Ethereum researchers are prioritizing quantum safety, stronger privacy, faster finality, and formal verification work.
• New state designs could help tokens, NFTs, and DeFi apps lower transaction costs significantly.

Ethereum co-founder Vitalik Buterin says Ethereum is preparing for a major long-term redesign under a plan called “Lean Ethereum.” In a July 4 post on X, Buterin said Ethereum researchers recently met in Berlin to continue planning the protocol’s future direction after earlier talks with client teams in Svalbard in April.

Buterin said the updated roadmap, shared through strawmap.org, shows that Lean Ethereum is not one single upgrade. Instead, it is a group of major changes expected to reach the network over the next three to four years. He described it as Ethereum’s third major version, following the Merge, which moved Ethereum away from proof-of-work mining.

Two weeks ago, Ethereum researchers met in Berlin to continue charting the protocol's long-term trajectory, following along discussions with client teams in Svalbard in April.

The updated strawmap is at https://t.co/HZEerH1xxI, and I attached a picture of it to this post.

My… pic.twitter.com/KPGayHSySf

— vitalik.eth (@VitalikButerin) July 4, 2026

Buterin Says Lean Ethereum Will Redesign Key Network Parts

According to Buterin, almost every major part of Ethereum’s protocol could change under the Lean Ethereum plan. One major area is verification. Ethereum may move toward recursive STARKs instead of direct re-execution. These proofs can help the network check activity more efficiently without making every participant repeat the same work in the same way.

The plan also gives more attention to quantum safety. Buterin said Ethereum researchers now see quantum-safe design as a much higher priority. The network aims to replace parts that could become vulnerable to future quantum computers with safer alternatives.

Consensus changes are also part of the plan. Buterin said Ethereum researchers are looking at faster and simpler finality, along with a design that separates data availability from finality. Finality is the point where transactions become very hard to reverse.

Privacy Becomes a Core Part of Ethereum’s Future

Buterin said privacy is no longer an afterthought for Ethereum. Researchers now treat it as a first-class goal when designing different parts of the network, including Frames, the mempool, and state tree changes.

He also pointed to formal verification as a key part of Ethereum’s future security work. Formal verification uses mathematical methods to check whether code behaves as expected. Buterin said this could make Ethereum researchers more comfortable with directly defining some parts of the protocol through bytecode.

The post also mentioned H-star, also known as Hegota. Buterin said it is probably Ethereum’s last major fork before the network starts moving strongly toward the Lean Ethereum direction. From I-star onward, most upgrades are expected to carry a clearer Lean Ethereum focus.

Ethereum’s State Upgrade Could Bring the Biggest Changes

Buterin said changes to Ethereum’s state may be the most disruptive part of the plan. Ethereum state refers to the data the network must keep, such as account balances, smart contracts, and other on-chain records.

Buterin said Ethereum researchers may keep the current dynamic state mostly as it is, but they may not scale it too much. At the same time, Ethereum could add new types of state that can handle much more data, although they would have some limits.

He also shared one possible example of Ethereum in 2030. The network could have around 2 TB of today’s dynamic state and about 100 TB of newer, more scalable state. Buterin said this newer state could work well for ERC-20 tokens, NFTs, and many DeFi projects. However, more complex systems, such as Uniswap contracts and on-chain order books, may still need the current flexible state model.

Buterin also made it clear that existing apps will not have to rewrite their code. Still, some projects may choose to update their design if it helps them lower costs. For example, an ERC-20 token could use a new storage method to reduce transaction fees by more than 10x.

Ethereum is also expected to raise gas limits, add more blob capacity, and reduce slot times several times over the next five years. Buterin said these changes will happen step by step, depending on network safety, client improvements, and protocol upgrades.