Ethereum Tests Larger Blocks on Sepolia with Key Upgrade

Ethereum is set to test significantly larger block sizes on its Sepolia testnet starting October 6, 2026. The network will increase the gas target from 60 million to 200 million, allowing for more computational work per block. This change is part of the Glamsterdam upgrade, scheduled to activate at 13:53:36 UTC. Hours before the upgrade, the Prysm validator client released version 7.2.1 to automatically adjust to the new gas limit, ensuring consistency across the network.

The higher gas target does not guarantee a threefold increase in transactions, as gas usage varies widely between simple transfers and complex smart contracts. The test aims to assess whether Ethereum's software can handle heavier blocks without slowing down the network or overburdening node operators.

Prysm’s update addresses a potential inconsistency where validators could propose blocks using the old 60 million gas default. The new version makes 200 million the default setting during the upgrade, though validators can still override it if needed. This change ensures a smoother transition and more reliable testing conditions.

The upgrade also includes technical adjustments like enshrined proposer-builder separation and block-level access lists to support the increased capacity. Developers will monitor the testnet for any issues, such as client disagreements, slow block propagation, or inaccurate gas estimates, before considering similar changes for the mainnet.