Ethereum Prepares for Glamsterdam Network Upgrade with Hoodi Testnet Activation Scheduled

Following its successful activation on the Sepolia testnet earlier this month on October 6, the highly anticipated Glamsterdam network upgrade has officially been scheduled for its next major milestone. The Ethereum core developer community has confirmed that Glamsterdam will activate on the Hoodi testnet at epoch 132,352, corresponding to slot 4,235,264. The deployment is set to take place on October 26, 2026, at precisely 17:42:48 UTC. Alongside this activation, the Hoodi testnet will experience a significant adjustment, raising its block gas limit to 200 million to align with testing parameters previously established on Sepolia. While testnet deployments are moving forward rapidly, a definitive mainnet activation date has not yet been determined by client development teams.

The Glamsterdam upgrade represents a major evolutionary step in Ethereum’s Layer 1 scaling roadmap. By combining the Amsterdam execution layer upgrade with the Gloas consensus layer upgrade, Glamsterdam introduces a suite of protocol-level changes designed to optimize block production, validation efficiency, and resource pricing. Headlining these changes are enshrined proposer-builder separation and block-level access lists, two structural adjustments aimed at supporting higher transaction throughput while maintaining the decentralization and integrity of network validation.

Enshrined Proposer-Builder Separation

At the core of the consensus-level updates is EIP-7732, which formally introduces enshrined proposer-builder separation (ePBS) into the Ethereum protocol. Up until now, the separation between block proposers and specialized block builders has largely relied on external, trusted middleware solutions. With ePBS, this vital relationship is embedded directly into the consensus mechanism itself.

Under the new protocol structure, a block proposer includes a builder’s commitment to an execution payload within a slot, and the builder subsequently reveals the full payload. The protocol handles the payment mechanics directly, reducing the network’s reliance on third-party relays and middleware. Furthermore, ePBS completely decouples consensus validation from execution validation. This separation grants validator nodes significantly more time to thoroughly validate execution payloads before attesting to them. A newly established payload timeliness committee will actively monitor and attest to whether builders reveal their payloads and associated blob data within the required timeframes. Validator operators and engineering teams maintaining builder infrastructure are strongly advised to review these new operational duties and protocol interfaces ahead of the testnet activation.

Block-Level Access Lists

Complementing ePBS on the execution side is EIP-7928, which introduces enforced block-level access lists (BALs). These lists comprehensively record all accounts and storage locations accessed over the course of a block, along with the resulting post-transaction state changes. By providing explicit data regarding state interactions, BALs empower client software to read state from disk in parallel, validate transactions simultaneously, and compute state roots with greater computational efficiency. Together, ePBS and BALs lay a robust technical foundation for scaling Ethereum’s execution capacity without placing an unmanageable hardware burden on node operators.

Gas Pricing and State Growth

Glamsterdam also brings vital reforms to gas accounting to better reflect the true resource costs associated with execution and state expansion. Through EIP-8037, the network increases and separately meters the financial and computational cost of creating new state, directly addressing long-term state bloat concerns. Simultaneously, EIP-8038 updates general state-access costs. Additional pricing modifications span intrinsic transaction gas, calldata handling, access lists, and overarching block gas accounting rules.

Application developers across the ecosystem are strongly encouraged to test their smart contracts and gas estimation logic against these updated parameters. Contracts that depend on fixed gas stipends, hardcoded gas limits, or legacy assumptions regarding remaining gas may require modifications to function correctly after the upgrade. Developers can consult the official Glamsterdam repricing impact guide to search for potentially affected contracts and review detailed testing guidance.

Developer and Validator Improvements

Beyond its major architectural changes, the Glamsterdam upgrade delivers several valuable enhancements for developers and validators alike. The specification introduces native ETH transfer logs, a dedicated slot-number opcode, an increased maximum contract size limit, a deterministic factory contract, and new stack-manipulation instructions. On the consensus side, changes include forward-compatible data structures, provisions to exclude slashed validators from the proposal queue, and an increase in the maximum exit and consolidation churn rates.

Security remains a top priority throughout the testing lifecycle. The Ethereum Bug Bounty Program is fully active for all Glamsterdam specifications and associated EIPs. Individual client implementations become eligible for bug bounty rewards as soon as their respective release versions are officially integrated into the testing infrastructure. Node operators and developers are reminded to utilize only officially designated client releases that explicitly confirm support for the scheduled Hoodi activation.

As the October 26 activation date approaches, non-staking node operators and validators on the Hoodi testnet must ensure that both their execution and consensus layer clients are updated prior to the target slot. While mainnet users, holders of ETH, and operators on networks other than Hoodi are not required to take immediate action, the broader community continues to monitor testnet performance closely as the path toward mainnet activation comes into view.