Ethereum's Glamsterdam hard fork — its largest protocol change since the Merge in September 2022 — hit a Sepolia testnet activation target of August 3, 2026, with mainnet deployment projected for September 16. The upgrade bundles 10+ EIPs that restructure block construction, enable parallel trans...
"There's a new chapter starting for the Protocol cluster." — Will Corcoran, Ethereum Foundation Protocol Cluster Lead
Ethereum's Glamsterdam hard fork — its largest protocol change since the Merge in September 2022 — hit a Sepolia testnet activation target of August 3, 2026, with mainnet deployment projected for September 16. The upgrade bundles 10+ EIPs that restructure block construction, enable parallel transaction execution, and target a gas limit increase from 60 million to 200 million per block.
Two headline proposals define the fork. EIP-7732 (Enshrined Proposer-Builder Separation) moves block building from off-chain relay infrastructure into the protocol itself, eliminating trust assumptions that currently govern approximately 90% of Ethereum blocks. EIP-7928 (Block-Level Access Lists) provides pre-execution dependency maps that enable concurrent transaction validation, pushing theoretical throughput toward 10,000 transactions per second. A companion package of gas repricing EIPs is projected to reduce L1 fees by up to 78% for complex smart contract interactions.
Devnet-7, characterized as the final dedicated development network before specification freeze, "held up well over the weekend with increased transaction loads," according to July 27 All-Core-Devs Testing notes. The upgrade arrives as ETH trades near $1,858, down over 45% from its October 2025 high above $3,600, and as co-founder Vitalik Buterin has publicly questioned whether L2 rollups remain the correct scaling paradigm.
Glamsterdam combines the "Amsterdam" execution-layer changes with the "Gloas" consensus-layer changes under a single hard fork umbrella, as outlined in EIP-7773. The upgrade was originally targeted for June 2026 but was pushed to Q3 after the Ethereum Foundation determined additional devnet testing was required.
Key dates:
The Ethereum Foundation named Will Corcoran, Kev Wedderburn, and Fredrik as new Protocol cluster leads on May 11, signaling a leadership transition concurrent with the upgrade's final development phase.
Approximately 90% of Ethereum blocks are currently produced through MEV-Boost, an off-chain relay system that separates block proposers from block builders. According to mid-2026 data, the top two builders — Titan and Quasar — construct roughly 73% of all blocks. Including the third and fourth builders (Eureka and BuilderNet) pushes that figure above 95%. The Herfindahl-Hirschman Index (HHI) for the builder market stands at approximately 3,892, well above the 1,800 threshold for highly concentrated markets.
EIP-7732 moves this entire auction mechanism on-chain. Under the current system, builders submit bids to trusted third-party relays. Under ePBS, builders submit bids directly to the Ethereum consensus layer, with cryptographic commitments enforced at the protocol level.
Technical specifications:
The stated objective is to reduce MEV extraction by up to 70%, according to multiple technical analyses. By eliminating trusted intermediaries, the upgrade addresses censorship risks inherent in concentrated relay infrastructure.
EIP-7928 introduces Block-Level Access Lists (BALs) — pre-execution maps of every account and storage slot touched within a block. These dependency maps are provided before execution begins, enabling three capabilities:
A companion networking protocol upgrade, EIP-8159 (eth/71), enables peer-to-peer sharing of these access lists. Both execution-layer and consensus-layer clients must implement these changes.
The combined effect enables the gas limit to scale from the current 60 million toward 200 million per block. Developers are currently testing at a 150 million reference block gas limit to calibrate state pricing. The Ethereum Foundation characterized the 200 million target as "a credible post-Glamsterdam" floor.
At the 200 million gas limit, the network targets 10,000 transactions per second, a 3.3x increase in block capacity.
Glamsterdam includes a suite of gas repricing EIPs designed to align economic incentives with modern hardware capabilities while preventing unbounded state growth:
| EIP | Function | Effect | |-----|----------|--------| | EIP-8037 | State creation gas cost increase | Targets 120 GiB/year state growth ceiling | | EIP-8038 | State-access gas cost update | Reflects current hardware performance benchmarks | | EIP-7976 | Calldata floor cost increase | Reduces DoS surface from calldata spam | | EIP-7981 | Access list cost increase | Adjusts EIP-2930 pricing | | EIP-2780 | Intrinsic transaction gas reduction | Standard ETH transfers up to 71% cheaper | | EIP-7954 | Max contract size increase | Raised from ~24 KiB to 64 KiB |
EIP-8037 introduces a fixed "cost per state byte" metric and separates state gas charges into a dedicated reservoir, decoupling state pricing from execution pricing. The intent is to allow gas limit expansion without proportional growth in the state database.
Net fee impact projections show reductions of up to 78.6% across complex smart contract interactions, according to Ethereum Foundation estimates. Simple ETH transfers between existing accounts become up to 71% cheaper under EIP-2780. However, operations that create new state — deploying contracts, writing to new storage slots — become more expensive, reflecting the long-term cost of state persistence.
Approximately 32% of total ETH supply — roughly 39 million ETH — is locked in proof-of-stake as of mid-2026. The validator entry queue had ballooned to 3,589,414 ETH with a 62-day wait time as of May 20, 2026, reflecting institutional demand through yield-distributing ETFs and corporate treasuries. Native staking APR has compressed to 2.78%, with MEV rewards adding 0.5–1%.
Glamsterdam introduces several changes relevant to staking operators:
New duties: All validators must participate in PTC attestation, a duty that introduces tighter timing windows. Validators running on high-latency connections face increased sensitivity.
Exit queue improvements: EIP-8061 increases exit and consolidation churn limits. EIP-8080 implements a "3 for 2" exchange rate between consolidation spots and standard exits, increasing exit speed by up to 2.5x during high-demand periods. What previously took weeks under current conditions may process in days.
Slashed validator restrictions: EIP-8045 excludes slashed validators from future block proposals, improving chain resilience during mass-slashing events.
Client update requirement: Stakers and node operators must update both consensus-layer and execution-layer clients before mainnet activation. Devnet-7 testing confirmed readiness for Prysm, Nimbus, and Lodestar. Teku was updating its branch, and Grandine was expected to reach readiness shortly.
Glamsterdam arrives in the context of a public reassessment of Ethereum's scaling roadmap. On February 3, 2026, Vitalik Buterin stated that many L2 solutions do not share Ethereum's security guarantees, criticizing ongoing reliance on multisig bridges and centralized sequencers. Progress toward fully decentralized L2s had been "far slower and more difficult than originally expected," according to Buterin.
Rather than viewing L2s as uniform Ethereum extensions, Buterin proposed reframing them as a spectrum of systems with varying trust assumptions. The implication for Glamsterdam is direct: the upgrade shifts Ethereum's scaling narrative back toward a high-performance L1, reducing the dependency argument for L2 offloading.
Arbitrum and Base have handled over 1,000 TPS, substantially exceeding L1's current capacity. Glamsterdam's 10,000 TPS target at a 200 million gas limit would invert that ratio, though achieving and sustaining the full gas limit increase will require post-upgrade validator coordination.
The 6-second slot proposal (EIP-7782) was shelved from Glamsterdam due to ZK proving implications and moved to the subsequent Hegotá upgrade. Fork-Choice Inclusion Lists (FOCIL) were similarly deferred to reduce upgrade complexity.
Devnet-7, the final dedicated devnet, "held up well over the weekend with increased transaction loads," according to the July 27 All-Core-Devs Testing call. Participation on Devnet-6 reached approximately 80%.
Stress testing at the Soldøgn interop event (concluded May 2) identified specific issues: Geth Builder and Nethermind were not consistently winning bids under dense block conditions, suggesting integration gaps in builder competitiveness under pressure. Multiple clients deployed patches during testing to close gaps exposed by load tests. A Nethermind storage-read disagreement during reverts was under investigation.
Primary risks to on-time mainnet delivery:
A mild specification freeze was expected following Devnet-7 launch, meaning structural changes should cease while minor parameter adjustments may still be accepted.
Glamsterdam represents a structural bet that Ethereum's L1 can absorb substantially more economic activity without outsourcing it to rollups operating under varying trust assumptions. The technical scope — enshrining block building, enabling parallel execution, tripling block capacity — is broad enough that schedule risk is non-trivial, particularly given incomplete client readiness and pending contract audits.
The September 16 mainnet target is aspirational. A September-to-December 2026 window remains the firmer base case across developer communications. If the upgrade activates on schedule and the gas limit reaches 200 million through subsequent validator coordination, it would mark the most significant expansion of Ethereum's L1 capacity since the network's inception.
ETH holders require no action. Stakers and node operators face mandatory client updates and a new PTC attestation duty. Scoping for the subsequent Hegotá upgrade — incorporating deferred proposals including 6-second slots and inclusion lists — is already underway.