- Ethereum’s Glamsterdam upgrade hits the Sepolia testnet on Oct 6! Introducing ePBS and Block-Level Access Lists for parallel L1 processing.
- Huge capacity test incoming: Sepolia will scale up to a 200M gas limit during the Oct 6 Glamsterdam hard fork.
- From Glamsterdam on Oct 6 to mainnet in late 2026, Ethereum is accelerating its scaling roadmap. Read what the new changes mean for dApps.
The Ethereum Foundation has announced the official activation date for the long-awaited Glamsterdam upgrade on the Sepolia testnet. This public milestone is a significant improvement for Ethereum’s L1 execution and consensus layer, aiming to go live at epoch 353,024 and slot 11,296,768, corresponding to October 6, 2026, at 13:53:36 UTC.
Glamsterdam follows the Fusaka framework closely and provides the same fundamental optimizations to maximize processing throughput, augment capacity, and manage state database growth. The upgrade is a combination of the “Amsterdam” updates on the execution layer and the “Gloas” updates on the consensus layer, bringing them together into one public network testing upgrade.
Core Structural Overhauls: ePBS and Parallel Processing
The core of the Glamsterdam upgrade is the underlying economics and computational efficiency of block production:
Enshrined Proposer-Builder Separation (ePBS): Proposed in EIP-7732, ePBS embeds the existing proposer-builder separation directly into the Ethereum protocol. The network’s solution alleviates the need for third-party middleware like MEV-Boost to be used by builders to receive payments, thereby decoupling consensus from execution verification. This gives validators some room to validate the computational resources without slowing down block production pipelines.
Block-Level Access Lists (BALs): Introduced via EIP-7928, BALs preemptively log exactly which accounts and storage locations will interact inside an individual block. Teams such as Nethermind performed client infrastructure software tests, during which they were able to pre-load these access lists so that nodes were capable of accessing state data in parallel instead of sequentially from storage disks.
Massive Gas Limit Strategy Signals Capacity Shift
In addition to structural plumbing, Glamsterdam represents a scaling paradigm shift to a multi-fold increase in block gas capacity. The public fork on Sepolia will launch with a target of 200 million gas limits. The testnet will use a voting system that gradually increases from the existing 60 million benchmark block by block, instead of being a sudden capacity boost that could cause network clients to become unstable.
This enables validators to set their resources safely according to the lengthened block propagation times, which are assumed to range from 2 to approximately 9 seconds during peak strain. This is paired with a revised gas pricing system that ensures that on-chain computational expenses are proportional to a growing state database, with the aim of achieving a stable growth of approximately 120 GiB per year.
Crucial Directives for Node Operators and Smart Contracts
As the October 6 deadline approaches, the Ethereum Foundation Blog highlights this as an explicit warning to infrastructure stakeholders. To prevent being split from the network, node operators running execution-layer and consensus-layer clients need to update them to compatible versions before the targeted epoch.
Further, decentralized application (dApp) developers need to audit their existing smart contracts. The foundational shifts in execution logic and data access pricing mean that contracts heavily reliant on fixed gas stipends, hardcoded gas limits, or legacy assumptions could fail or become economically unviable post-activation. Meanwhile, regular ETH holders and mainnet users require no action at this time.
The Road Ahead: Hoodi, Mainnet, and the Post-Hegotá Era
The validator-focused Hoodi testnet (planned for late October) and the mainnet rollout of Ethereum itself are still open-ended, but the developers are pushing for the full public mainnet launch to be completed by the end of Q4 2026.
Core developers are already planning for the next major Ethereum upgrade in 2027, known as Hegotá. Ethereum co-founder Vitalik Buterin recently observed that Hegotá may well represent the network’s final “normal” hard fork. The subsequent versions will focus entirely on specialized new mathematics and architecture advances such as recursive STARK proofs, automatic formal verification models, and high-level quantum-secure cryptography.
