Ethereum’s Glamsterdam Upgrade Goes Live on Sepolia Test Network

Ethereum’s next big upgrade, called Glamsterdam, went live on the Sepolia testnet on October 6, 2026. The activation happened at 13:53 UTC. Glamsterdam is a hard fork that combines the Gloas consensus layer upgrade with the Amsterdam execution layer upgrade. It follows the Fusaka upgrade from December 2025 and focuses on making Ethereum’s base layer faster.

Two headline changes

The upgrade has two main features. The first is enshrined proposer-builder separation, known as EIP-7732. This brings block building directly into Ethereum’s rules. Today, validators rely on outside middlemen called relays to build blocks. Glamsterdam removes that need and gives validators more time to check transactions. The second is block-level access lists, or EIP-7928. These let network computers process transactions in parallel instead of one by one. This should speed things up a lot.

Gas limit jumps to 200 million

On Sepolia, the gas limit jumped from about 60 million to 200 million at activation. Gas measures the computing work in each block. A bigger limit means more room for payments and trades before fees rise. In early tests, blocks used between 52 million and 92 million gas, well below the new cap. On the live network, the 200 million target would be reached slowly over time, not all at once. The upgrade also changes gas prices for some tasks. Creating new storage will cost nearly five times more, which affects airdrops and token minting.

What comes next

In total, Glamsterdam includes 18 core improvement proposals. The Ethereum Foundation warns that some smart contracts may need updates if they rely on fixed gas amounts. Regular ETH holders do not need to do anything. Anyone asking you to upgrade your coins is a scammer. The next testnet, Hoodi, is expected around October 27. The mainnet upgrade is targeted for the fourth quarter of 2026. After that, the next upgrade is called Hegota, which Vitalik Buterin says may be Ethereum’s last normal fork.

Why Glamsterdam matters for users

Most users will not notice Glamsterdam directly, but they should feel its effects over time. Parallel transaction processing means the network can handle more activity at once. A higher gas limit means more space in each block before fees spike. Together, these changes should make Ethereum cheaper and faster to use during busy periods. That is good news for anyone trading tokens, using DeFi apps, or minting NFTs.

Developers need to pay attention now. The Ethereum Foundation warns that the gas repricing may break some smart contracts. Contracts that assume fixed gas costs for creating storage could fail or become expensive. Teams should test their apps on Sepolia as soon as possible. The Foundation has published guides to help developers prepare. With mainnet only months away, there is no time to waste.