Ethereum Glamsterdam upgrade on Hoodi testnet

Ethereum developers have scheduled the Glamsterdam fork on the Hoodi testnet for October 26, 2026. Hoodi is the network's second and final public testnet, and the upgrade concerns ETH and the Ethereum base layer.

What is happening

Glamsterdam is the network upgrade that follows Fusaka. Its name combines Amsterdam, the execution layer side, and Gloas, the consensus layer side. The upgrade is already live on the Sepolia testnet, where it activated on October 6, 2026, as scheduled. Researcher Christine D. Kim reported on October 9 that the Sepolia upgrade "went smoothly."

After the Sepolia activation, developers set Monday, October 26 for Hoodi, with client releases expected by October 16. The scope is tracked in EIP-7773, which lists 18 core changes. The main ones are enshrined proposer-builder separation (EIP-7732), block-level access lists (EIP-7928) and a repricing of gas for creating, reading and writing state (EIP-8037 and EIP-8038).

No mainnet date has been agreed. The Ethereum Foundation has said Hoodi and mainnet dates were not yet decided, and ethereum.org lists only a fourth-quarter 2026 target. A draft scheduling proposal on GitHub floats December 1, 8 and 9 as possible mainnet slots. Several proposals, including EIP-2780 and EIP-8037, remain in Last Call review until November 1, so the scope may still change.

Why it matters

Hoodi is the last public rehearsal before mainnet, and its results will inform the mainnet date. One open question is the builder market. Early Sepolia data suggested only four or five builders were active, with many blocks built locally, and developers have raised concerns about attacks on a design that asks builders for a stake of 1 ETH. Hoodi is expected to be a more telling test of how the new block-building flow works with real participants.

For holders and stakers, the upgrade brings faster validator exits under EIP-8061 and a shorter weak subjectivity period for nodes that go offline, from about 15.7 days to about 7 days. For traders and users, the stated goal is to allow a gas limit floor of 200 million after the upgrade, compared with today's 60 million default. Whether fees change will depend on demand, and the proposed gas repricing would make creating new state, such as contracts and accounts, considerably more expensive.

Key details

• Date: October 26, 2026 (Hoodi testnet activation); client releases expected by October 16
• Project: Ethereum
• Coins: ETH
• Category: Testnet
• Status: Confirmed for Hoodi; mainnet date not yet decided
• Source: https://yellow.com/research/glamsterdam-ethereum-18-change-bet-base-layer