Ethereum Glamsterdam Upgrade Countdown Starts for Sepolia Testnet Launch

The Ethereum community is preparing for the Glamsterdam upgrade, set to launch on the Sepolia testnet on October 6, 2026, at 13:53:36 UTC. This upgrade combines the Amsterdam execution layer upgrade with the Gloas consensus layer upgrade, introducing key changes like enshrined proposer-builder separation (ePBS) and block-level access lists (BALs). These changes aim to improve how blocks are produced and validated, ultimately supporting greater Layer 1 throughput.

Before the testnet launch, non-staking Sepolia node operators are advised to update their execution and consensus layer clients to versions that support the upcoming activation. Stakers on Sepolia must also ensure their beacon node and validator client are updated and review any necessary adjustments for the new ePBS duties and tooling changes.

The Glamsterdam upgrade includes several improvements, such as EIP-7732, which separates block proposers and builders, and EIP-7928, which introduces enforced block-level access lists. Together, these changes provide a framework for scaling execution capacity while maintaining practical block validation for node operators. Additional updates include adjustments to gas accounting, higher maximum contract sizes, and new consensus changes like forward-compatible data structures.