Ethereum's next hard fork, Glamsterdam, targets a mainnet launch in the first half of 2026 and represents the network's most structurally ambitious upgrade since the Merge. The fork enshrines proposer-builder separation (ePBS) directly into the consensus layer via EIP-7732, introduces block-level...
"Every compromise of values that Ethereum has made up to this point... we are making that compromise no longer." — Vitalik Buterin, Ethereum Co-Founder
Ethereum's next hard fork, Glamsterdam, targets a mainnet launch in the first half of 2026 and represents the network's most structurally ambitious upgrade since the Merge. The fork enshrines proposer-builder separation (ePBS) directly into the consensus layer via EIP-7732, introduces block-level access lists (BALs) via EIP-7928 to enable parallel transaction execution, and recalibrates gas costs via EIP-7904 to produce a projected 78% fee reduction. The gas limit is slated to rise from 60 million to 200 million per block, targeting throughput of 10,000 transactions per second — roughly 10x the current capacity.
As of the Ethereum Foundation's Checkpoint #9 report on April 10, 2026, developers were aiming to launch the first unified Glamsterdam devnet within days, contingent on stabilizing the ePBS devnet. The tentative June 2026 mainnet target remains aspirational; Q3 is considered more realistic by core developers. ETH trades at approximately $2,313 as of April 22, 2026, with Citi's institutional desk setting a near-term base case of $3,175 ahead of the upgrade.
The upgrade directly addresses a structural problem: three block builders currently control more than 80% of all PBS blocks, and MEV relays facilitate production of over 85% of blocks on mainnet. Whether ePBS redistributes or further concentrates that power remains an open question that academic research has flagged but not resolved.
Glamsterdam is a portmanteau of Gloas and Amsterdam — the consensus-layer and execution-layer codenames for this fork, respectively. It follows Pectra (May 2025) and Fusaka (December 2025). The next upgrade after Glamsterdam, Hegota (Heze + Bogota), is tentatively slated for late 2026.
Vitalik Buterin outlined eight EIPs defining the upgrade's scope in late February 2026. Two anchor the release:
A package of gas repricing proposals — led by EIP-7904 and bundled under EIP-8007 — rounds out the technical scope.
At the Hong Kong Web3 Carnival on April 20, 2026, Buterin stated that Ethereum's core short-term goals include continuing to increase the gas limit for scaling, launching zkEVM for verifiable computation, and initiating preparations for quantum resistance. He added: "If you just replicate Ethereum, scale it up by 100 times, make it more centralized, and that's it, it's meaningless."
Under the current system, block production relies on an external sidecar called MEV-Boost, maintained by Flashbots. Validators running MEV-Boost outsource block construction to specialized builders who compete to assemble the most profitable block, then relay the winning bid to the proposer.
This system works but introduces dependencies:
EIP-7732 moves this market on-chain. Block builders assemble transactions, cryptographically seal the contents, and submit bids. Proposers (validators) select the highest-paying bid without being able to see or alter the transaction contents. Transactions are revealed only after the commitment is locked.
The stated goals: eliminate the 80–90% reliance on third-party relays, reduce censorship vectors, and formalize MEV distribution within the protocol itself.
Ethereum's EVM currently executes transactions sequentially. Each transaction must complete before the next begins, because the EVM cannot know in advance which state (storage slots) a transaction will access.
EIP-7928 addresses this by attaching Block-Level Access Lists to each block — explicit records of all accounts and storage locations accessed during execution, along with post-execution values. According to data cited in the EIP discussion, 60–80% of transactions access disjoint storage slots, making them candidates for parallel execution. The remaining 20–40% can be parallelized using post-transaction state diffs.
BALs add approximately 70 KiB per block on average. The tradeoff: marginal bandwidth cost in exchange for significantly reduced block processing time. BALs also enable parallel disk reads, parallel state root computation, and what developers call "executionless state updates" — nodes can update state without re-executing the full block.
Multiple client teams are actively prototyping the implementation. The BAL-specific devnet has been running separately from the ePBS devnet, and the Checkpoint #9 report describes BAL devnets as "making predictable progress through expectedly difficult problems."
EIP-7904 recalibrates gas costs for opcodes, precompiles, memory expansion, and data access operations. The Ethereum Foundation's Gas Cost Estimator project benchmarked actual computational effort across seven widely used EVM implementations to establish empirical baselines.
The result: many gas prices set years ago no longer reflect execution costs on modern hardware. The recalibration produces a projected 78.6% reduction in gas costs for both simple ETH transfers and complex smart contract interactions, according to analysis of the repricing specifications.
Practical impact estimates:
The gas limit is targeted to rise from 60 million to 200 million per block. Combined with BAL-enabled parallelism, throughput targets 10,000 TPS — up from approximately 1,000 TPS today.
EIP-7954: Maximum Contract Size Increase Raises the maximum contract code size from 24 KiB to 32 KiB and initcode size from 48 KiB to 64 KiB. Ecosystem developers have lobbied for this inclusion, according to the Checkpoint #9 report, and it is "likely to be prioritized."
EIP-8007: Gas Repricings Bundle A meta-EIP that packages the gas repricing proposals as a coordinated set rather than individual changes, ensuring consistency across the recalibration.
| Milestone | Status (as of April 2026) | |---|---| | ePBS devnet | Running, stabilization in progress | | BALs devnet | Running, "predictable progress" | | Unified Glamsterdam devnet | Targeted for mid-April 2026 | | Public testnet (Holesky, Sepolia) | Pending post-devnet | | Mainnet fork | June 2026 aspirational; Q3 realistic |
Until April 2026, testing was split across separate networks: one for ePBS (epbs-devnet) and one for BALs (bals-devnet). The first unified devnet merges all Glamsterdam components into a single environment. Once stable, the sequence is: client releases, final security reviews, testnet deployment, mainnet fork date announcement.
The Ethereum Foundation's Checkpoint #9 described ePBS as a "major sticking point" — the protocol must now handle disagreement or failure between proposers and builders acting in sequence, a scenario that did not exist in the previous consensus architecture. On the execution side, BALs represent "a fundamental rethinking of how gas and state access work."
The stated purpose of ePBS is decentralization — removing reliance on external relays that constitute single points of failure. However, a January 2026 academic paper modeling ePBS in the presence of MEV concluded that while ePBS reduces validator-side concentration, it "significantly amplifies profit and content centralisation" among builders, because access to private order flow confers a structural bidding edge that compounds over time.
Buterin himself acknowledged this tension. In an X post prior to the upgrade's formal unveiling, he warned that Glamsterdam "could unintentionally concentrate power among a small group of sophisticated block builders." He proposed two supplementary mechanisms:
By mid-2025, according to Bitfinex research, over 50% of high-value Ethereum transactions were routed through private channels to avoid MEV extraction. The so-called "free option problem" — where builders can delay committing to blocks during volatility — affects approximately 0.82% of blocks on average, spiking to roughly 6% during volatile periods.
Whether ePBS solves or reshuffles these dynamics depends on implementation details and market structure responses that cannot be fully modeled in advance.
Ethereum's staking ecosystem has expanded to approximately 35.86 million ETH staked (28.91% of total supply), secured by roughly 1.1 million active validators, according to beaconcha.in data. Average staking yield sits at 3.3% annually.
ETH trades at approximately $2,313 as of April 22, 2026, with a 14-day RSI of 39.07 — approaching oversold territory. The token is down significantly from its all-time highs, and the Glamsterdam upgrade is one of few catalysts on the near-term horizon.
The broader Ethereum roadmap beyond Glamsterdam includes the Hegota upgrade (targeting FOCIL, additional scaling), and longer-term goals of full quantum resistance, formal verification of the entire protocol, and maximized decentralization.
Glamsterdam addresses real structural deficiencies in Ethereum's block production pipeline and execution layer. The upgrade's technical ambition — enshrining PBS, enabling parallel execution, repricing gas across the entire opcode set — is substantial. If delivered as specified, it would represent the most significant change to Ethereum's L1 architecture since the transition to proof of stake.
The risks are equally concrete. ePBS implementation is proving more complex than anticipated. The centralization concerns Buterin himself has raised about builder dominance do not have solutions shipping in this fork. And the gap between aspirational June timelines and realistic Q3 estimates suggests the development process still carries meaningful execution risk.
The upgrade's economic implications — cheaper L1 transactions, higher throughput, restructured MEV flows — will materially affect DeFi protocol economics, Layer 2 fee structures, and validator revenue models. How those effects distribute will depend on details that remain in active development.