Ethereum's Glamsterdam hard fork — the largest protocol upgrade since The Merge in September 2022 — has slipped from its original H1 2026 target to Q3 2026 after the Soldøgn Interop devnet concluded on May 2. The upgrade introduces three structural changes: enshrined Proposer-Builder Separation (...
"We ended the week with a stable multi-client Glamsterdam devnet running the latest ePBS, repricing, and block access list specs, along with benchmarking data to anchor a credible gas limit proposal." — Ethereum Foundation, Soldøgn Interop Recap, May 2, 2026
Ethereum's Glamsterdam hard fork — the largest protocol upgrade since The Merge in September 2022 — has slipped from its original H1 2026 target to Q3 2026 after the Soldøgn Interop devnet concluded on May 2. The upgrade introduces three structural changes: enshrined Proposer-Builder Separation (ePBS) via EIP-7732, Block-Level Access Lists (BALs) via EIP-7928, and benchmarked gas repricing via EIP-7904. If activated, the gas limit rises from 60 million to 200 million per block, targeting approximately 10,000 transactions per second — roughly 10x current throughput — with a projected 78% reduction in Layer 1 gas fees.
Over 100 core contributors gathered in Longyearbyen, Svalbard for the Soldøgn Interop, producing six devnets (bal-devnet-4 through bal-devnet-6, glamsterdam-devnet-0 through glamsterdam-devnet-2) in a single week. By the end of the interop, nearly all Ethereum execution and consensus clients were running together on glamsterdam-devnet-2 with external builder pipelines tested end-to-end. Three deliverables were locked: a 200M gas floor target, stable ePBS implementations with external builders, and final EIP-8037 repricing numbers.
The economic implications extend across the entire Ethereum stack. Over 90% of validators currently route block construction through MEV-Boost's off-chain relay infrastructure. Glamsterdam moves this process on-chain, eliminating trusted intermediaries and formalizing MEV handoff rules at the consensus layer. For Layer 2 networks — which collectively hold $48 billion in TVL as of May 2026 — expanded blob capacity from the current 21-blob maximum to a target of 72+ blobs per block will reduce data availability costs, directly lowering transaction fees on Arbitrum, Base, Optimism, and zkSync.
Vitalik Buterin outlined eight Ethereum Improvement Proposals in late February 2026 that define Glamsterdam's full scope. The three headline proposals address block construction, state access, and gas pricing. Five supporting EIPs handle storage economics, inclusion guarantees, and validator hygiene.
Core EIPs:
Supporting EIPs:
Under EIP-8037, contract deployment costs rise approximately 10x and new account creation about 8.5x, while code deposit metering remains separate so that large contracts — such as Uniswap V4 pools — remain deployable.
The current Ethereum block production pipeline depends on MEV-Boost, an off-chain middleware used by over 90% of validators. Block builders compete to construct the most profitable blocks, and trusted relays — centralized intermediaries — match these builders with block proposers (validators). According to on-chain data, the top four builder organizations (Flashbots, builder0x69, Bloxroute, and beaverbuild.org) construct nearly 50% of all blocks and account for approximately 70% of execution block rewards.
This architecture creates three structural risks: relay downtime causes validators to miss slots (validators depend on 100% relay uptime), concentrated builders can censor transactions (sanctioned transaction types have been excluded in practice), and the entire MEV supply chain operates outside the protocol's trust model.
EIP-7732 replaces this off-chain stack with an on-protocol commit-reveal mechanism. Builders submit block commitments directly to the consensus layer. Proposers select commitments without seeing transaction contents, and validators verify blocks against committed headers. The external block builder pipeline has completed end-to-end testing across nearly all client implementations during the Soldøgn Interop. The data propagation window expands from approximately 2 seconds to roughly 9 seconds under ePBS, allowing the network to safely handle higher transaction throughput without compromising consensus finality.
For validators, this means reduced operational complexity — no more dependency on external MEV relay infrastructure. For the network, it means the MEV supply chain is governed by protocol rules rather than informal trust agreements.
Ethereum currently processes transactions sequentially within each block. A transaction modifying a smart contract's storage must complete before the next transaction touching the same contract can begin. This serial execution is the primary throughput bottleneck on Layer 1.
EIP-7928 introduces Block-Level Access Lists, which require each block to declare upfront which accounts, storage slots, and code segments it will read or write. This declaration enables three parallel processing capabilities:
Developers building on Ethereum will need to structure smart contracts to avoid "hot spots" — storage slots accessed by many concurrent users. Contracts that declare clean access patterns will benefit most from parallel execution. The practical effect: more transactions per block at the same or lower gas cost per transaction.
Ethereum's current gas cost schedule assigns fixed costs to EVM opcodes based on estimates that, in many cases, predate modern hardware capabilities. Some operations are overpriced relative to their actual compute cost; others are underpriced, creating potential attack vectors.
EIP-7904 recalibrates gas costs using empirical data. The benchmark data was generated by running the EEST benchmark suite with Nethermind benchmarking tooling, collected between January 5 and January 22, 2026. Operations were selected for repricing based on their estimated million-gas-per-second (Mgas/s) performance, with a target of 60 Mgas/s — 3x the current 20 Mgas/s baseline.
The combined effect of repriced opcodes, BALs, and the gas limit increase from 60M to 200M is projected to reduce gas costs by approximately 78% for both simple ETH transfers and complex smart contract interactions. Current gas prices on Ethereum sit at roughly 0.1–0.6 gwei as of late May 2026 — already low by historical standards — suggesting the network has significant headroom for throughput increases without proportional fee increases.
EIP-8037 complements this by introducing state creation cost increases that prevent the higher gas limit from causing runaway state bloat. The fixed cost-per-state-byte model targets approximately 60 GiB of annual state growth at a 300M gas block limit, establishing a sustainable ceiling.
As of May 2026, 73 active rollups collectively secure over $48 billion in TVL, according to L2BEAT data. Market concentration is significant: Arbitrum One holds approximately $16.9 billion (40–44% market share), Base holds $12.8 billion, and the two optimistic rollups together account for roughly 77% of all L2 DeFi liquidity. The remaining field fragments across Optimism ($1.91B), Starknet ($617M), Linea ($421M), and zkSync Era ($404M).
Glamsterdam affects Layer 2 economics through two channels:
Blob expansion: The current maximum of 21 blobs per block (raised from 15 in a recent parameter-only fork) is targeted to increase to 72 or more under Glamsterdam. More blob capacity reduces data availability bidding wars between rollups, directly lowering the cost of posting compressed transaction data back to Ethereum L1. Industry estimates suggest blob fees could contribute 30–50% of total ETH burn by late 2026, depending on L2 activity scaling.
Cheaper L1 settlement: The 78% gas fee reduction on L1 directly benefits rollups that settle proofs and state roots on mainnet. For zero-knowledge rollups (zkSync, Starknet, Linea), proof verification gas costs are a material operating expense. Lower L1 gas translates to lower per-transaction overhead passed to end users.
The combined effect could accelerate L2 adoption by reducing the cost premium that Layer 2 networks carry relative to alternative Layer 1 chains. Whether this narrows the competitive gap or simply lowers costs for existing L2 users remains to be observed.
Glamsterdam's original target was H1 2026, with June cited as an aspirational mainnet activation date. Following the Soldøgn Interop (concluded May 2, 2026), Q3 2026 is now the more realistic window, according to multiple developer sources and a CoinMarketCap analysis of the upgrade timeline.
Devnet progress:
Remaining steps before mainnet:
The Ethereum Foundation's May 11 protocol update confirmed these milestones while also announcing a leadership transition for the Protocol Cluster. Three new leads were named: Will Corcoran (zkVM proofs and post-quantum consensus research), Kev Wedderburn (zkEVM development), and Fredrik (protocol security and the "Trillion Dollar Security" initiative).
Several features originally scoped for Glamsterdam have been moved to Hegotá, Ethereum's second major 2026 upgrade, positioned as a late-2026 "cleanup and hardening" fork.
Deferred to Hegotá:
The decision to defer these features reflects a risk management approach: Glamsterdam already introduces three structural changes to Ethereum's execution and consensus layers. Adding storage migration and inclusion list enforcement would compound testing complexity and delay deployment further.
Glamsterdam represents the most significant structural change to Ethereum since Proof-of-Stake. The upgrade addresses three long-standing constraints simultaneously: sequential execution, off-chain MEV infrastructure, and misaligned gas pricing. The 200M gas limit, ePBS, and BALs are interdependent — parallel execution requires deterministic state access, higher gas limits require accurate opcode pricing, and moving MEV on-chain requires expanded block processing windows.
The slip to Q3 2026 is consistent with Ethereum's historical pattern of delayed but ultimately successful upgrades. The Soldøgn Interop demonstrated functional multi-client interoperability with ePBS and BALs running concurrently, a prerequisite for testnet progression. The remaining gates are public testnet activation, dual audits, and client readiness confirmation.
For the $48 billion Layer 2 ecosystem, cheaper L1 settlement and expanded blob capacity are direct cost reductions. For validators, ePBS simplifies operations by removing relay dependency. For developers, BALs and repriced opcodes alter smart contract optimization strategies. For the network as a whole, the question is whether 10x throughput at 78% lower costs is sufficient to recapture economic activity that has migrated to alternative Layer 1 chains — or whether it merely lowers operating costs for the existing user base.
The data will answer that question. Glamsterdam sets the conditions.