Ethereum’s next major protocol upgrade, dubbed Glamsterdam, began running on the Sepolia testnet on Tuesday, signaling the last major rehearsal before the changes are moved to mainnet.
Testnet launch details
The deployment occurred at 13:53 UTC, as announced by community contributor Pooja Ranjan on X. The Sepolia rollout follows a series of earlier testnet trials and is intended to validate the upgrade’s functionality under realistic conditions. After Sepolia, developers will assess performance on the Hoodi testnet before setting a definitive mainnet activation date.
Core changes in Glamsterdam
Glamsterdam targets three primary enhancements to Ethereum’s layer-1 architecture. First, Enshrined Proposer-Builder Separation (EIP-7732) decouples the roles of block proposers and builders, while also separating consensus validation from execution validation. This gives validators additional time to verify execution payloads and reduces contention during block production.
Second, the upgrade implements enforced block-level access lists (EIP-7928). These lists record which accounts and storage slots a block touches, along with resulting state changes. By making this information available, client software can read state data from disk in parallel, validate transactions concurrently, and compute state roots more efficiently.
Third, the Ethereum Foundation has set a new gas-limit floor of 200 million for Glamsterdam, a significant increase from the current roughly 60 million limit. The higher ceiling is expected to raise throughput without raising the protocol’s gas-limit ceiling, supporting larger blocks and more parallel processing.
Roadmap and upcoming upgrades
Glamsterdam follows the Fusaka upgrade and serves as a bridge toward the next planned hard fork, Hegotá. After the Sepolia trial, the Hoodi testnet will host further validation, after which a mainnet launch date will be announced. Hegotá, currently in the scoping phase, is being evaluated through a review of 66 proposals, several of which focus on adding privacy features to the protocol.
Why it matters
The changes introduced by Glamsterdam aim to make Ethereum more scalable and efficient. By separating proposer and builder responsibilities and enabling parallel transaction validation, the network can handle higher transaction volumes without increasing the gas limit. The elevated gas-limit floor further prepares the chain for larger blocks, potentially reducing congestion and lowering fees for users. Successful deployment on Sepolia brings the upgrade one step closer to mainnet, setting the stage for continued evolution toward higher throughput and broader functionality.
