Ethereum’s next major network upgrade is entering its final phase and its first public test now has a date. The Glamsterdam fork is scheduled for Sepolia on October 6, 2026, while mainnet is expected in the fourth quarter of 2026 with no official date yet, according to U.today.
The assessment comes from Ethereum Foundation researcher Toni Wahrstätter, who said in a September 26 post on X that work on Glamsterdam and EIP-7928, better known as Block-Level Access Lists, is near the finish. He described Glamsterdam as likely one of the largest forks the network has seen and said the extended development time should be justified by the result. Testing has so far stayed on devnets, with public exposure beginning at Sepolia.
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Key facts
- Sepolia fork date: October 6, 2026; mainnet expected in Q4 2026 with no official date yet, per U.today.
- Ethereum Foundation researcher Toni Wahrstätter said Glamsterdam and EIP-7928 (Block-Level Access Lists) are close to the final mile.
- Wahrstätter said the fork should bring a significant throughput increase through parallelism and faster, simpler sync via snap v2.
- He also described the upgrade as future-compatible with zkEVMs, partially stateful nodes and inclusion lists.
- Cofounder Vitalik Buterin said Hegota, the fork planned for next year, may be Ethereum’s last ‘normal’ fork.
What the fork is built to fix
Glamsterdam is aimed at three targets: processing speed through parallelization, added capacity, and avoiding database growth, the concern known as state bloat. Enshrined proposer-builder separation (ePBS) is described as the headliner because it reworks the block validation pipeline and trims trust assumptions, while Block-Level Access Lists are the mechanism that delivers parallel execution.
The combination points to a change in how blocks are built and validated rather than a routine parameter tweak, which is why the testing window runs through devnets and a public testnet before mainnet deployment.
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Buterin maps out life after Hegota
In a separate post on X, Buterin sketched what he called, in substance, the meaning of what is planned for Ethereum beginning with the fork after Hegota. He framed the project as no longer only a blockchain but a hybrid design combining blockchain with modern cryptography, which he said enables more powerful properties than either component alone.
Referring to Strawman, the site that holds Ethereum’s longer-range draft roadmap, Buterin said Hegota — planned for next year — may be the last fork a developer from 2015 would recognize. Work after it is expected to lean on recursive STARKs, automated formal verification and heavily optimized consensus algorithms intended to make Ethereum quantum-safe. He pointed to PeerDAS as the point where Ethereum started shifting from a blockchain into something broader, and said that transformation becomes the main narrative once Hegota is done. The payoff he described is cheaper, more scalable and more private high-security computation than the earlier technology stack could deliver.
Why it matters
The dates matter to app developers, staking operators and node runners, because devnet-only testing has limited how much real-world load the Glamsterdam code has faced. A Sepolia fork opens that testing to a public network ahead of mainnet, giving operators time to update clients and check how parallel block processing behaves under normal use. The ePBS and BAL changes also affect the block-building path, which is where validators, builders and relays interact most directly.
Parallelization targets throughput within a block rather than adding independent chains, so applications already calibrated to block-level execution keep the same environment while gaining capacity. The sustainability goal addresses node storage requirements, one of the constraints a growing state places on people willing to run a full node.
What to watch
The immediate marker is the October 6, 2026 Sepolia fork, under a week away, followed by the still-unscheduled mainnet launch in Q4 2026. Devnet progress on EIP-7928 and any client or testnet issues between those two events are the signals to track.
Source: U.Today
