Protocol Announcements

The Glamsterdam upgrade on Hoodi, previously scheduled for October 26, 2026 at 17:42:48 UTC (epoch 132,352), has been postponed. A new activation date has not been set. This update supersedes the schedule and activation instructions in the Hoodi testnet announcement.

Update — October 22, 2026: The October 26 Hoodi activation has been postponed, including the scheduled gas-limit increase to 200M. The schedule and activation instructions below have been superseded. See Glamsterdam on Hoodi Postponed for details and operator guidance. Following its activation on Sepolia on October 6, the Glamsterdam network upgrade is now scheduled for the Hoodi testnet. Glamsterdam advances Ethereum's L1 scaling roadmap with enshrined proposer-builder separation, block-level access lists, and changes to gas pricing that better reflect the cost of execution and state growth. The Glamsterdam network upgrade is scheduled to activate on Hoodi at epoch 132,352, slot 4,235,264 (October 26, 2026, 17:42:48 UTC). At the same epoch, Hoodi's gas limit will be raised to 200M. See the activation table below for the deployment

Glamsterdam follows the Fusaka upgrade, advancing Ethereum's L1 scaling roadmap with enshrined proposer-builder separation, block-level access lists, and changes to gas pricing that better reflect the cost of execution and state growth. The Glamsterdam network upgrade is scheduled to activate on Sepolia at epoch 353,024, slot 11,296,768 (October 6, 2026, 13:53:36 UTC). See the activation table below for the deployment schedule. Hoodi and mainnet activation dates have not yet been decided. Sepolia-compatible client versions will be added to the client release tables as they are confirmed. Node operators must update both their execution and consensus layer clients before activation.

tl;dr: Meet Platåberget: Glamsterdam's (Gloas + Amsterdam) early testing ground open to public participation. This upgrade comes with breaking changes for application developers. Notably, any tool that relies on a hardcapped maximum gas limit (think wallets, indexers and gas estimators) will break and needs to be updated. Please use this early opportunity to test! Platåberget is a short-term testnet aimed for testing changes by the community. Unlike the short-lived devnets before it, Platåberget is intended to run for a few months, giving the community a stable place to experiment with post-Glamsterdam Ethereum, and an opportunity to test and break things before Glamsterdam goes live on Ethereum's longer-lived testnets, Sepolia and Hoodi.

Fusaka follows this year's Pectra upgrade, representing a major step forward in Ethereum's scaling roadmap that improves L1 performance, increases blob throughput, and enhances user experience. The Fusaka network upgrade is scheduled to activate on the Ethereum mainnet at slot 13,164,544 (December 3, 2025, 21:49:11 UTC). Fusaka also introduces Blob Parameter Only (BPO) forks to safely scale blob throughput after PeerDAS activation. These are minimal, config-only upgrades that adjust the blob target/max and fee update fraction. See the activation table below for further details. The Fusaka mainnet client releases are listed below.

Fusaka follows this year's Pectra upgrade, representing a major step forward in Ethereum's scaling roadmap by introducing PeerDAS and key improvements that enhance blob throughput, L1 performance, and user experience. This post announces the testnet activation schedule for the first three testnets, beginning with Holesky at slot 5,283,840 (October 1, 2025, 08:48:00 UTC). See the activation table below for the complete Sepolia and Hoodi timeline. Fusaka also introduces Blob Parameter Only (BPO) forks to safely scale blob throughput after PeerDAS activation. These are minimal, config-only upgrades that adjust the blob target/max and fee update fraction. The Fusaka testnet client releases are listed below. Once all three testnets have successfully upgraded, a mainnet activation slot will be chosen.

As previously announced, the Holešky testnet has reached its planned end-of-life date and will be sunset shortly. The vast majority of remaining validator nodes will be shut down 2 weeks after the Fusaka upgrade has finalized on Holešky. After this, Holešky will no longer be supported by client, testing or infrastructure teams. Following the launch of the Hoodi testnet in March 2025, infrastructure providers and staking operators have had the opportunity to migrate their testing operations.

As of today, all Ethereum execution clients support partial history expiry in accordance with EIP-4444. While work on full, rolling history expiry is ongoing, users can expect to reduce the disk space required for an Ethereum node by 300-500 GB by removing the block data prior to the Merge. This will allow a node to fit comfortably on a 2 TB disk. See below for information on each specific client.