Ethereum's Glamsterdam hard fork — the network's largest protocol upgrade since The Merge — remains in active devnet testing as of June 2026, with mainnet activation likely slipping from its original H1 2026 target into Q3. The upgrade centers on two structural changes: EIP-7732 (Enshrined Propos...
"Finally, the block building pipeline. In Glamsterdam, Ethereum is getting ePBS, which lets proposers outsource to a free permissionless market of block builders. This ensures that block builder centralization does not creep into staking centralization." — Vitalik Buterin, Ethereum Co-Founder
Ethereum's Glamsterdam hard fork — the network's largest protocol upgrade since The Merge — remains in active devnet testing as of June 2026, with mainnet activation likely slipping from its original H1 2026 target into Q3. The upgrade centers on two structural changes: EIP-7732 (Enshrined Proposer-Builder Separation) and EIP-7928 (Block-Level Access Lists). Together, they aim to raise the gas limit from 60 million to 200 million per block, enable parallel transaction execution, and reduce Layer 1 gas costs by an estimated 78%.
The stakes are high. ETH trades near $1,988 with a market capitalization of approximately $239 billion — down from peaks above $4,800 in late 2021. Ethereum's base layer currently handles roughly 15-30 transactions per second. Glamsterdam targets 10,000 TPS. The question is whether the engineering can deliver before competing Layer 1s and Ethereum's own Layer 2 ecosystem make the upgrade moot.
Glamsterdam is built around two "headliner" proposals. Over 30 additional EIPs were considered; most were excluded.
EIP-7732: Enshrined Proposer-Builder Separation (ePBS). Currently, 80-90% of Ethereum block production depends on offchain relays like MEV-Boost. Three builders produced nearly 80% of all Ethereum blocks between late 2023 and early 2024, according to relay data. EIP-7732 moves the proposer-builder coordination directly into the consensus protocol. It introduces a commit-reveal pipeline for block construction, onchain builder identity with signed bids, and a Payload Timeliness Committee (PTC) for validation.
EIP-7928: Block-Level Access Lists (BALs). This proposal requires blocks to declare their state access patterns upfront in headers, including a hash commitment (BAL root). The mechanism enables pre-fetching of working state before execution begins and supports parallel transaction execution. Under the current sequential model, each transaction must wait for the previous one to complete. BALs convert execution into a dependency graph, allowing independent transactions to process simultaneously.
Additional EIPs under consideration: EIP-7904 (repricing EVM opcodes using empirical client benchmarks), EIP-8037 (increasing gas costs for account/storage creation), EIP-8038 (raising gas costs for cold storage access), and EIP-7954 (expanding maximum contract bytecode size). These have been bundled into EIP-8007 for gas repricing coordination.
The upgrade also requires new infrastructure: Engine API extensions for BAL payload delivery, an eth/71 wire protocol for peer-to-peer BAL distribution, and a requirement that execution layer clients retain BALs for a minimum of 3,533 epochs.
Development has progressed through multiple phases, though slower than originally projected.
January 2026: The All Core Developer Consensus (ACDC) call revealed that planned features may be incompatible with the mid-2026 deadline. Ethereum Foundation protocol prototyping lead Toni Wahrstätter reported that an engine API change was impacting consensus layer client implementations for EIP-7928. December 2025 stress tests by EthPandaOps revealed problems in the Teku client. Nimbus and Lodestar teams completed preliminary work; other client teams remained behind schedule.
February 2026: Vitalik Buterin outlined eight EIPs defining Glamsterdam's scope. Developers set end-of-February as a decision deadline for feature inclusion.
Late April 2026: The first generalized Glamsterdam devnet launched. Until this point, testing had been split across separate networks — one for ePBS (epbs-devnet) and one for BALs (bals-devnet). The generalized devnet merged all components into a single environment for the first time.
May 2, 2026: The Soldøgn Interop concluded in Svalbard, Norway. Eight different software clients achieved interoperability by the second day. The team spent the remaining days stress-testing. The interop established consensus on three parameters: a post-upgrade gas limit floor of 200 million, a stable external builder workflow for ePBS, and finalized EIP-8037 repricing parameters.
Current status (June 2026): Devnet-4 testing is complete. Devnet-5 is underway. Public testnet activations on Holesky and Sepolia have not yet been scheduled. No mainnet fork epoch has been announced.
The Ethereum Foundation's April Checkpoint #9 blog post stated directly that Q2 2026 mainnet deployment "appears unlikely given current progress velocity." Most developers now expect a July-to-September window for mainnet activation.
Maximal Extractable Value (MEV) — the profit validators and builders extract by reordering, inserting, or censoring transactions — runs approximately $180 million per month on Ethereum, according to searcher profit data from late 2025 and early 2026. Between December 2025 and January 2026, searchers extracted approximately $24 million in MEV profit over a 30-day period.
The current relay-dependent system concentrates power. Three builders controlling 80% of block production creates a single point of failure and raises censorship concerns. ePBS addresses this by eliminating the need for trusted third-party relays.
However, research published on arXiv in January 2026 identified a paradox: while ePBS redistributes responsibilities between builders and proposers, it may amplify profit centralization. The Gini coefficient for builder profits rises from 0.1749 under standard Proof of Stake (without ePBS) to 0.8358 under ePBS, according to the paper. A small number of efficient builders would capture most value via MEV-driven auctions.
Buterin has acknowledged this risk. His March 2026 roadmap proposes a multi-stage approach: ePBS in Glamsterdam as the first step, followed by Fork-Choice Enforced Inclusion Lists (FOCIL) to ensure censorship resistance, and eventually encrypted mempools to prevent frontrunning and sandwich attacks. FOCIL was originally considered for Glamsterdam but was deferred to avoid delaying the upgrade. The Base engineering team publicly warned that adding FOCIL alongside ePBS could push Glamsterdam beyond 2026.
Ethereum's gas limit has already undergone significant increases: from 30 million to 35 million in February 2024, 35 million to 45 million in July 2024, and 45 million to 60 million in November 2024 — a 2x increase in a single year. Ethereum Foundation researcher Toni Wahrstätter called it "only the beginning."
Glamsterdam targets a 3.33x increase to 200 million gas per block. The Ethereum Foundation's 2026 roadmap set a more conservative public target of "toward and beyond 100 million," though the Soldøgn Interop established 200 million as the floor.
The projected impact on fees: multi-hop DeFi trades would drop from $5-15 to $0.30-0.80 per transaction. Simple transfers would fall below $0.10. These projections assume the gas limit increase is paired with BAL-enabled parallel execution; the gas limit alone would not achieve these reductions without the throughput improvements.
A critical caveat from the Ethereum Foundation: gas repricing via EIP-8037 will simultaneously increase costs for account and storage creation. This prevents unbounded state growth — a necessary tradeoff. The net effect for users should still be substantially lower fees, but certain operations (deploying new contracts, creating new accounts) will become more expensive to discourage state bloat.
Glamsterdam's impact extends to Ethereum's Layer 2 ecosystem. The upgrade is expected to reduce rollup data posting costs by approximately 70%, according to developer projections, continuing the trajectory begun by EIP-4844 (Proto-Danksharding) in March 2024.
Expanded data blob capacity means rollups — Arbitrum, Optimism, Base, and others — would face fewer bidding wars for data availability space. Lower settlement costs on the base layer translate directly to lower transaction fees for end users on L2s.
This creates a competitive dynamic. If Ethereum L1 fees drop to $0.10-0.80 per transaction, the economic case for some L2 usage narrows. L2s would need to compete on execution speed, application-specific features, or sub-cent fees rather than simply offering cheaper access to Ethereum settlement. The upgrade effectively compresses the fee differential that justified much of the L2 buildout.
Several major proposals were removed from Glamsterdam and reassigned to Hegotá, Ethereum's planned H2 2026 upgrade:
Hegotá has been repositioned as a late-2026 fork focused on these deferred items plus state expiry groundwork. Whether that timeline holds depends on how quickly Glamsterdam ships and stabilizes.
Over 30 proposals were excluded from Glamsterdam entirely, including reduced slot times and multidimensional gas metering. As Galaxy Research analyst Christine Kim noted regarding the scope management challenges: "Some of my readers who have followed my newsletters from Pectra upgrade days may be groaning inwardly and thinking, 'Not again!'"
Glamsterdam represents a deliberate bet that Ethereum's base layer still matters. At a time when L2 ecosystems process the majority of Ethereum-aligned transactions and competing L1s offer sub-second finality, the upgrade attempts to make Ethereum L1 itself competitive on cost and throughput.
The engineering is substantial. Parallel execution via dependency graphs, protocol-level proposer-builder separation, and a 200-million gas limit would collectively represent the largest single throughput expansion in Ethereum's history. But the delays are real — from the original H1 2026 target to what now appears to be a Q3 landing — and the MEV centralization research suggests ePBS alone does not solve the builder concentration problem.
ETH holders and ecosystem participants face a familiar dynamic: the upgrade is technically ambitious, the testing is proceeding methodically, and the timeline continues to stretch. Whether Glamsterdam delivers on its throughput promises will determine whether Ethereum L1 recaptures economic activity from its own L2 ecosystem — or whether the fee compression simply accelerates competition among rollups operating on an increasingly commoditized settlement layer.