Ethereum's Sepolia Testnet Activates Glamsterdam Upgrade with Increased Gas Limit

On October 6, 2026, at 13:53:36 UTC, Ethereum's Sepolia testnet activated the Glamsterdam upgrade, marking a significant enhancement in its operational capacity. This upgrade allows validators to opt into a new gas limit of 200 million, a substantial increase from the previous limit of approximately 60 million.

The Glamsterdam upgrade merges two critical components: the Amsterdam upgrade, which focuses on the execution layer for processing transactions and running smart contracts, and the Gloas upgrade, which pertains to the consensus layer where validators confirm the validity and order of blocks. A key feature of this upgrade is the enshrined proposer-builder separation (ePBS), as defined in EIP-7732. This structural change allows for a more efficient block production process by separating the roles of builders and proposers within the protocol.

Additionally, the upgrade introduces block-level access lists and a round of gas repricings. Access lists enable nodes to anticipate which parts of Ethereum's state a block will interact with, while gas repricings adjust operational costs to better reflect the actual computational work required.

The increase in gas limit is significant, representing more than a threefold capacity enhancement. However, it is important to note that this change is currently optional for validators, who can signal their preference for the higher limit. As of now, there are no immediate changes to the mainnet gas limits, and the timeline for a potential mainnet activation of Glamsterdam has not been established.

Prior to this public testnet activation, developers conducted thorough testing in earlier environments, ensuring the core functionality was validated. The successful implementation of the Glamsterdam upgrade on Sepolia is a critical step in assessing Ethereum's capacity for handling more complex transactions and could influence future developments on the mainnet.