Glamsterdam Upgrade Targets Ethereum's Sepolia Testnet on Oct. 6

Ethereum developers have scheduled the network's next major upgrade, Glamsterdam, to activate on the Sepolia testnet on Oct. 6.

The update will introduce enshrined proposer-builder separation, moving the handoff between specialized block builders and validators into Ethereum's protocol.

Glamsterdam will also introduce block-level access lists, which record the accounts and storage locations used during each block, as well as changes to gas pricing to better reflect data creation and access costs on the network.

The upgrade will require Sepolia node operators to update both their execution-layer and consensus-layer clients before activation. Ethereum co-founder Vitalik Buterin noted that Glamsterdam is not the final major fork, with developers targeting 2027 for Hegotá, which could be the last 'normal' fork before development shifts toward recursive STARKs.