Ethereum’s core developers launched the first generalized devnet for the Glamsterdam upgrade in the final week of April 2026. The move joins previously separate tests for ePBS and BALs in one environment. It marks Ethereum’s biggest integrated testing phase since the Merge in September 2022.
The upgrade combines “Gloas,” the consensus layer, and “Amsterdam,” the execution layer. Together, they form Glamsterdam, Ethereum’s next hard fork. Developers currently target mid-2026, with June as the aspirational window.
nixo.eth, an Ethereum Foundation developer, announced the launch in a thread on X. The post spread widely across the Ethereum community. Protocol watchers had tracked the milestone for months.
Until April 2026, Ethereum tested its major Glamsterdam features on separate networks. One focused on ePBS. The other focused on BALs. The generalized devnet now brings those components together for the first time.
Glamsterdam focuses on three goals: more reliable block production, parallel transaction execution, and lower gas fees. Its two headline proposals are EIP-7732, known as ePBS, and EIP-7928, known as Block-Level Access Lists.
Today, 80% to 90% of Ethereum blocks rely on external relay systems such as MEV-Boost. Those off-chain systems add centralization risk and require trust in third parties. ePBS moves proposer-builder separation into the protocol itself.
That design removes intermediaries from block construction. It also enables trustless on-chain payments between builders and proposers. In turn, Ethereum can make block production more transparent and more auditable inside the protocol.
BALs address execution. They require blocks to declare every account and storage slot they will touch. That lets Ethereum pre-load data from disk before execution starts. As a result, the network can run non-conflicting transactions in parallel. Today, Ethereum processes them in sequence. Under BALs, execution can follow a dependency graph across multiple threads.
The projected outcome is up to 10,000 transactions per second and a 78% reduction in execution costs. The text says a DeFi user who now pays $4 to $8 per swap could face far lower costs.
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On April 10, the Ethereum Foundation published Checkpoint #9 and described development as slow but steady. It also identified ePBS as the main bottleneck. The challenge lies in coordinating two parties within a consensus.
Next, developers plan client releases, security audits, and public testnets on Holesky and Sepolia. Only after those stages can they set an official mainnet date. June remains possible, while Q3 appears more realistic in the text.
Meanwhile, markets have started reacting. On April 14, 2026, ETH broke a bearish channel that had held since August 2025. It then gained 9.2% in a single session. Analysts cited $3,400 as the next technical target.
The ETH/BTC ratio has reached its highest level of 2026. The text also says BitMine, the firm linked to analyst Tom Lee, has accumulated more than 3 million ETH. That activity points to rising attention around the upgrade.
The text also cites earlier upgrade cycles. ETH gained 60% in the pre-fork window before Dencun in the first quarter of 2024. It also rallied 10% after Shapella was activated in 2023.
Beyond Glamsterdam, the roadmap continues. Vitalik Buterin has identified FOCIL as the headline feature of the following upgrade, Hegotá. He also lists encrypted mempools and a longer-term ZK-EVM path tied to a 1000x scalability target.
Ethereum’s first generalized Glamsterdam devnet brings ePBS and Block-Level Access Lists into one live testing environment, marking a major step toward lower gas fees, faster execution, and more reliable block production. The next key signals now are public testnet launches and progress toward a mainnet timeline.