A combination of the consensus layer upgrade known as Gloas and the execution layer upgrade named Amsterdam has yielded Ethereum’s next major system overhaul: Glamsterdam. The prospective upgrade has just cleared its initial primetime test, marking a notable milestone for the leading smart contract network as it targets a significant expansion in processing capacity.
Glamsterdam went live on the Sepolia testnet, with the blockchain successfully finalizing blocks through the cutover transition without encountering any critical operational hurdles. While the deployment remains confined to testnet environments for now, the implications of its performance are substantial for the broader Ethereum ecosystem. Researchers and core developers have begun highlighting the fork’s potential to dramatically reshape network throughput.
Ethereum Foundation researcher Toni Wahrstätter pointed to the upgrade as the potential opening for Ethereum’s largest throughput increase since its inception. Based on the technical architecture of the fork, Glamsterdam is engineered to support a gas limit of approximately 200 million, representing roughly a 3.3-fold increase over the current mainnet baseline of 60 million gas. For historical context, the Ethereum mainnet operated with a 30 million gas limit for years before validators raised it to 60 million across three distinct adjustments in 2025. Even the substantial capacity expansion delivered by the London upgrade in 2021, which doubled the maximum block size, kept the base target fixed at 15 million.
Despite the high ceiling, the upcoming fork will not simply flip a switch to instantly expand Ethereum’s capacity threefold. Instead, the upgrade modifies the underlying mechanisms of block production, establishing an environment where producing much larger blocks becomes technically safe. Following the deployment, validators will ultimately decide whether and how rapidly to raise the operational gas limit based on network conditions.
Glamsterdam’s Core Proposals and Architectural Shifts
The forthcoming fork bundles a total of 18 Ethereum Improvement Proposals, though three primary proposals carry the majority of the technical weight required to achieve these performance gains.
The first core pillar is enshrined proposer-builder separation, commonly referred to as ePBS. Under the current network design, the vast majority of Ethereum blocks are constructed by specialized builders and subsequently passed to validators through trusted intermediaries known as relays. Through EIP-7732, the consensus mechanism will change so that the block proposer commits to a builder’s signed cryptographic bid, while the builder reveals the full block data afterward.
This procedural shift means that the resource-intensive task of verifying a block’s transactions no longer needs to be crammed into the tight roughly four-second attestation window currently required. Under the new proposal, validators will instead be granted approximately nine seconds to perform these validations safely.
The second significant pillar introduced in Glamsterdam involves block-level access lists, known as BALs. This feature provides a new capacity for parallel transaction processing across the network. Currently, Ethereum client software processes a block’s transactions sequentially, one by one, because nodes cannot predict in advance which state variables each transaction will modify. EIP-7928 mandates that every block will ship alongside a comprehensive map of all the state data it touches, accompanied by the resulting values.
Armed with this structural guide, client software can prefetch necessary data and validate multiple transactions in parallel. To use a manufacturing analogy, ePBS provides quality control inspectors with additional time to perform thorough checks, while BALs supply the operational floor with everything required to run multiple assembly lines simultaneously.
In addition to these structural changes, the upgrade introduces modifications to smart contract limits and state repricing. EIP-7954 raises the maximum contract size from 24 kilobytes to 64 kilobytes, easing a restrictive cap that has historically forced complex decentralized applications to split their code across multiple contracts. Simultaneously, the network will increase the economic cost of creating new state. Under EIP-8037, generating a fresh storage slot will jump from 20,000 gas to 97,920 gas, while standard Ether transfers to existing accounts will remain priced at 21,000 gas under EIP-2780.
Tracking the Sepolia Testnet Deployment and Path to Mainnet
The initial Glamsterdam block on the Sepolia testnet launched with a 60 million gas limit matching the current mainnet parameters. Following the launch, Sepolia’s gas limit climbed to the 200 million target approximately 11 hours after the fork concluded and has successfully maintained that level since.
Because each block proposer is restricted to nudging the gas limit by roughly 0.1 percent per block, an ideal scenario where every proposer increased the limit on every block would have allowed Sepolia to complete the transition in approximately four hours. The process ultimately took more than twice that duration, a delay attributed in part to two popular consensus clients, Prysm and Teku, which maintained validator gas limits at 60 million post-fork unless operators explicitly opted into the 200 million setting.
Early data shared from the testnet environment suggests the new execution levers are already yielding performance improvements. Client software is handling each unit of gas faster than before the fork. For example, executing a 40-million gas block that previously required Go-Ethereum roughly 115 milliseconds now takes approximately 30 milliseconds. Although derived from a limited dataset across a small number of nodes, the initial metrics indicate a promising trajectory for client efficiency.
Looking ahead, the Sepolia deployment serves as the first step in a broader testnet rollout. The Hoodi testnet is slated next for its own Glamsterdam deployment, with late October tentatively discussed as a target window, though timelines remain subject to change. Mainnet activation continues to be targeted for some point in the fourth quarter of 2026.
The timeline has experienced previous shifts, as Glamsterdam was originally penciled in for the first half of 2026, and Sepolia’s specific testnet fork slipped from early August to October. Consequently, developers acknowledge that further timeline adjustments remain possible as testing progresses.
Broader Economic and Ecosystem Implications
The implementation of Glamsterdam will inevitably introduce new operational dynamics and technical considerations for developers across the ecosystem. Various Ethereum developer tools, wallets, indexers, and gas estimators that rely on assumptions of a fixed maximum gas limit will require software updates to prevent disruptions. The Ethereum Foundation has previously issued advisories emphasizing the need for infrastructure providers to maintain compatibility with the evolving network specifications.
Furthermore, with the structural repricing directed at network state growth, on-chain activities that generate large volumes of new accounts or storage—such as token airdrops, massive NFT mints, and fresh wallet creation—will incur higher costs. In contrast, standard peer-to-peer transfers will remain economical under the revised fee schedules.
These intricate adjustments represent minor friction points compared to the broader structural advantage: the Ethereum layer-one network is preparing to offer significantly greater block space. This expansion provides room for ecosystem experimentation across decentralized finance, traditional financial integrations, and novel applications alike.
During periods of high demand, network congestion has historically driven transaction fees higher and priced out various use cases. The increased throughput enabled by Glamsterdam is designed to accommodate demand surges smoothly without destabilizing baseline gas markets. As the development community advances through its remaining testnet deployments, the focus remains on preparing the mainnet infrastructure to support the next generation of decentralized applications.
Tokenomics & Digital Assets
Tokenomics & Digital Assets
Tokenomics & Digital Assets
