Ethereum’s Glamsterdam upgrade has officially gone live on the Sepolia test network, marking a late-stage rehearsal ahead of a broader rollout to the network’s next environments and, ultimately, mainnet.

According to blockchain data from the Sepolia Blockscout explorer, Glamsterdam launched on Tuesday at 1:53 pm UTC (epoch 353,024). The upgrade is part of Ethereum’s ongoing layer-1 scaling roadmap, and the Ethereum Foundation outlined its goals in a Sept. 28 blog post.

Key takeaways

Glamsterdam is now running on Sepolia at epoch 353,024, continuing Ethereum’s staged testnet-to-mainnet upgrade plan.
The upgrade’s core protocol changes include enshrined proposer-builder separation (EIP-7732) and block-level access lists (EIP-7928).
EIP-7732 is designed to improve block production and validation by more cleanly separating roles and reducing validation bottlenecks.
EIP-7928 adds block-level access lists to support more efficient parallel state access and validation.
After developers test Glamsterdam further on the Hoodi testnet, they will set the final activation date for mainnet.

Glamsterdam reaches Sepolia as final testing nears

The Sepolia activation is one of the last major testnet launches before Glamsterdam’s schedule moves forward. Once the upgrade has been validated on Sepolia, developers plan to determine its activation date on the Hoodi testnet. Only after that step will they finalize the timeline for Glamsterdam’s mainnet activation.

In its Sept. 28 announcement, the Ethereum Foundation described Glamsterdam as a meaningful step toward improving network scalability and efficiency at the layer-1 level. The update is positioned as one of the most consequential Ethereum protocol changes scheduled for 2026, aiming to better align execution costs with real computation while improving overall throughput.

Enshrined proposer-builder separation and why it matters

Glamsterdam’s headline change, enshrined proposer-builder separation, is implemented via EIP-7732. The proposal builds on the consensus-layer structure by separating block proposers and builders more formally within Ethereum’s protocol rules.

The EIP also separates consensus validation from execution validation. The practical result, according to the upgrade design, is that validators should have more time to perform execution payload validation—an adjustment intended to reduce timing pressure that can otherwise limit how efficiently blocks are produced and checked.

Ethereum’s current operation is described as “single-lane,” where transactions are handled in a single order. Ethereum’s longer-term scaling approach relies on parallel processing to increase transactions per second and enable bigger block sizes without raising the gas limit. EIP-7732 is intended to be part of the infrastructure that makes those higher-throughput goals more achievable by improving how validation and block construction interact.

Block-level access lists for faster parallel execution

The second major change in Glamsterdam introduces enforced block-level access lists through EIP-7928. Under this design, each block includes a record of which accounts and storage locations were accessed during that block, along with post-transaction state changes.

Ethereum’s rationale for adding these block-level access lists is to help clients read and compute state more efficiently. By knowing which parts of state a block is expected to touch, clients can potentially fetch relevant data from disk in parallel, validate transactions in parallel, and compute state roots with less friction.

In other words, rather than relying on clients to infer state dependencies after the fact, Glamsterdam makes those dependencies explicit at the block level—an approach that can improve performance and responsiveness as Ethereum pushes toward more concurrent processing.

The Ethereum Foundation also previously discussed a key configuration detail for Glamsterdam: it set a 200 million gas limit floor for the upgrade. In a May blog post referenced in coverage of the milestone work, the Foundation said this would provide a substantial post-upgrade speed boost compared with the then-current gas limit of around 60 million.

What comes next: Hoodi testing and Hegotá planning

With Glamsterdam now active on Sepolia, the next decision point is Hoodi. Developers will use the testnet period to assess readiness and determine Glamsterdam’s activation date there before setting the final mainnet schedule.

Meanwhile, attention is already turning toward the next major steps after Glamsterdam. Following mainnet activation, Ethereum development is expected to move toward implementing Hegotá as the subsequent major upgrade, with Ethereum developers having started scoping the protocol work earlier this year. Coverage noted that developers began reviewing dozens of proposals—66 in total—to narrow them down, including several aimed at introducing additional privacy capabilities.

For readers tracking Ethereum’s roadmap, the next watch items are straightforward: performance and stability results from Hoodi during Glamsterdam testing, and what the team reports as they move from testnet parameters to mainnet activation timing. That sequence will help determine whether the upgrade’s ePBS and block access list changes deliver the efficiency gains Ethereum is targeting.