Ethereum developers are preparing a pivotal testnet activation that could shape the network’s next Layer 1 scaling phase. The Glamsterdam upgrade is scheduled to go live on the Sepolia testnet on October 6, 2026 at 13:53:36 UTC, while mainnet and Hoodi activation dates remain undecided.
The upgrade combines the Amsterdam execution-layer changes with the Gloas consensus-layer package. It introduces enshrined proposer-builder separation (ePBS), moving builder commitment, delivery and payment into the protocol, and block-level access lists that help nodes organize validation and read state data in parallel. The Ethereum Foundation says these changes create room for greater execution capacity, though ordinary ETH holders do not need to take action for the Sepolia activation.
Glamsterdam also reprices gas for storage-related work. EIP-8037 increases and separately accounts for state creation costs, while EIP-8038 updates charges for reading and writing stored information. A simple ETH transfer to an existing ordinary account keeps the 21,000 execution gas specification, but contracts that create significant new storage or use hardcoded gas allowances may need testing and changes. The Foundation’s analysis replayed historical mainnet transactions under the proposed schedule; most produced unchanged outcomes, though some required higher gas limits and a smaller group remained potentially broken.
Validators face a separate coordination choice. Although Prysm 7.2.0 and Teku 26.9.1 support Glamsterdam, they will continue using a 60 million gas preference after activation unless validators explicitly override their settings. Prysm operators must use version 2 proposer settings or the keymanager API, while Teku validators can change the default in their validator configuration. The 200 million gas target is therefore not automatic: under EIP-8261, the gas-limit schedule is optional and does not alter consensus-validity rules. Sepolia’s realized gas limit would move gradually as validators propose blocks.
Ethereum’s block gas limit has already climbed from 30 million toward 36 million in February 2025, later reaching 45 million before Fusaka client releases adopted 60 million as their default. Fusaka also introduced a 16.7 million gas cap for individual transactions, meaning higher block limits primarily create room for more aggregate activity rather than allowing single transactions to expand without restraint. The Sepolia test will give developers and validators an early signal on whether clients follow the new rules together and whether wallets estimate fees correctly under the revised gas schedule.
