Ethereum "Glamsterdam" Upgrade Goes Live on Sepolia Testnet

Ethereum has activated its Glamsterdam upgrade on the Sepolia testnet, advancing the network's phased path from test environments toward a future mainnet rollout. Data from the Sepolia Blockscout explorer shows the upgrade triggered on Tuesday at 1:53 pm UTC at epoch 353,024. The Ethereum Foundation outlined Glamsterdam's objectives in a Sept. 28 blog post as part of its layer-1 scaling roadmap. The upgrade centers on two major protocol changes: enshrined proposer-builder separation (EIP-7732) and block-level access lists (EIP-7928). Glamsterdam enters late-stage testing Sepolia is among the final major testnet milestones before the schedule progresses. After validation on Sepolia, developers plan to run further testing on the Hoodi testnet and then set an activation date there. Only after Hoodi will the team finalize the timing for mainnet activation. In its Sept. 28 update, the Ethereum Foundation positioned Glamsterdam as a significant layer-1 efficiency and scalability step and described it as one of the most consequential Ethereum protocol changes expected in 2026. The stated aim is to better align execution costs with real computation while improving throughput. EIP-7732: enshrined proposer-builder separation Glamsterdam's headline change, enshrined proposer-builder separation, is implemented via EIP-7732. The proposal more formally separates block proposers and block builders within Ethereum's protocol rules, and it also separates consensus validation from execution validation. The intended practical effect is to give validators more time to validate execution payloads, reducing timing pressure that can create validation bottlenecks and constrain efficient block production. Ethereum's current execution model is often described as "single-lane," processing transactions in a single order. The longer-term scaling direction targets more parallel processing to raise transactions per second and support larger blocks without increasing the gas limit. EIP-7732 is designed to help make those higher-throughput goals more achievable by improving the interaction between validation and block construction. EIP-7928: block-level access lists The second key change, EIP-7928, introduces enforced block-level access lists. Under the design, each block records which accounts and storage slots were accessed during the block, along with post-transaction state changes. Ethereum's rationale is that making state dependencies explicit can help clients read and compute state more efficiently. With clearer expectations about which parts of state a block will touch, clients may be able to fetch data from disk in parallel, validate transactions in parallel, and compute state roots more smoothly. Gas limit floor set at 200 million The Ethereum Foundation has also highlighted a configuration detail tied to Glamsterdam: a 200 million gas limit floor. In a May blog post referenced in reporting on the milestone work, the Foundation said this would deliver a substantial post-upgrade speed boost compared with the then-current gas limit of around 60 million. Next steps: Hoodi testing and Hegotá planning With Sepolia now running Glamsterdam, the next checkpoint is Hoodi. Developers will use the Hoodi testnet period to evaluate performance and stability before locking in the mainnet timeline. Attention is also shifting to what follows Glamsterdam. After mainnet activation, Ethereum development is expected to progress toward Hegotá as the next major upgrade. Developers began scoping that work earlier this year and have been reviewing 66 proposals, including several focused on adding privacy capabilities. For roadmap watchers, the near-term signals are Hoodi's testing results and developer updates as the process moves from testnet parameters to a mainnet activation date, which will indicate whether ePBS and block-level access lists deliver the efficiency gains Ethereum is targeting.