Ethereum activated the Glamsterdam upgrade on the Sepolia testnet at 13:53:36 UTC on October 6, allowing validators to increase the block gas limit target from roughly 60 million to 200 million. The change puts more than three times the network's previous execution capacity through a public stress test.
The Prysm consensus client shipped version 7.2.1 on October 5, one day before activation, so validators automatically propose blocks at the 200 million gas setting once the fork triggers at epoch 353,024. Operators running the earlier 7.2.0 release would have defaulted to 60 million gas unless they changed their proposer configuration manually, according to release notes. Other clients such as Teku remained at 60 million unless configured otherwise, but Prysm's last-minute patch helped ensure the network received more consistent exposure to larger blocks.
A block gas limit sets the maximum computation that transactions inside a single block can consume. Raising Sepolia's limit from about 60 million to 200 million creates more room for swaps, stablecoin transfers and smart contract interactions when demand for block space is high. The trade-off is that larger blocks place heavier hardware demands on validators, which is precisely what the test is meant to measure.
The upgrade also includes changes to how certain operations are priced, including EIP-8037, which ties gas costs more closely to the amount of permanent state data an operation creates. Ethereum Foundation developer Parithosh Jayanthi said during earlier testing that high-level computation would become cheaper while state creation would become more expensive under the repricing changes. Developers have warned that contracts relying on fixed gas assumptions or 2,300-gas stipends may need modifications before Glamsterdam reaches mainnet.
Sepolia is not the first environment to run Glamsterdam near the 200 million level. Devnet 11, a controlled development network, moved from 60 million to 200 million gas during a rehearsal in September using 84,000 validators across several clients. Ethereum's mainnet raised its gas limit to 60 million in November 2025 after more than 513,000 validators signaled support for the change.
Ethereum's official Glamsterdam schedule lists only Sepolia for October 6, with activation dates for the Hoodi testnet and mainnet still undecided. The Ethereum Foundation has said separate announcements will follow after client teams agree on those deployments. Work beyond Glamsterdam is already examining similar constraints, with proposals being considered for the Hegota upgrade including further gas-pricing changes.
