Ethereum Foundation sets Glamsterdam for Sepolia on October 6

The Ethereum Foundation's official Glamsterdam testnet announcement confirms the network upgrade activates on Sepolia at epoch 353,024 — slot 11,296,768 — on October 6. Following Fusaka, Glamsterdam advances Ethereum's L1 scaling roadmap with enshrined proposer-builder separation (ePBS), block-level access lists, and gas pricing changes that better reflect the cost of execution and state growth.

Client teams are shipping fork support ahead of the testnet: Geth v1.17.6 schedules Amsterdam on Sepolia at timestamp 1791294816 (October 6) and tells Sepolia node operators to upgrade beforehand, while the EF's Platåberget testnet serves as an early public testing ground for the combined Gloas and Amsterdam upgrades.

Glamsterdam introduces breaking changes for application developers: any tool that relies on a hardcapped maximum gas limit — wallets, indexers, gas estimators — must be updated, since repricing means gas is no longer capped at a fixed maximum. Sepolia activation remains the near-term milestone ahead of mainnet.