The Ethereum Foundation opened the Platåberget testnet on August 17 for public testing ahead of the Glamsterdam mainnet fork scheduled for August 20, according to the announcement on the foundation's blog.
Glamsterdam introduces three core changes to Ethereum's consensus and execution layers. The upgrade activates proposer-builder separation via EIP-7732, which decouples block construction from block proposal to address centralization pressures in MEV extraction. It adds block-level access lists through EIP-7928 to improve transaction processing efficiency. The upgrade also implements gas repricing adjustments to recalibrate fee structures across different transaction types.
Platåberget functions as a final validation environment before mainnet deployment. The testnet operates with the same configuration as mainnet and allows developers and node operators to identify issues, test client implementations, and verify validator behavior under the proposed rule changes. Public access removes barriers to participation that normally gate testnet testing to core infrastructure operators.
The two-day window between testnet launch and mainnet fork is narrow compared to historical Ethereum upgrades. Earlier major upgrades like Shanghai in April 2023 ran testnets for weeks before deployment. Glamsterdam's compressed timeline comes from the Ethereum Foundation's assessment that the changes are lower-risk relative to consensus-layer overhauls, though validators still have until August 20 to flag critical bugs or compatibility problems.
EIP-7732, the proposer-builder separation mechanism, has been a research priority for the foundation since 2023. It aims to reduce the MEV advantage held by specialized block builders who currently dominate transaction ordering. EIP-7928 mirrors upgrades to execution-layer gas economics previously deployed on testnets. Both mechanisms shipped on the Sepolia testnet in June 2026 without incident, providing six weeks of observation data before mainnet activation.
The August 20 fork will apply to all Ethereum validators and node operators. Clients that fail to upgrade to compatible versions will fall out of consensus and stop receiving new blocks. The Ethereum Foundation has published updated releases for all major clients, Geth, Prysm, Lighthouse, and Nimbus, with Glamsterdam support built in.
Three weeks separated Platåberget's public announcement and mainnet deployment, a faster-than-typical progression for a multi-component upgrade. Ethereum completed Shanghai in a similar timeframe in 2023, though Shanghai covered staking withdrawals alone, a narrower scope than Glamsterdam's three independent features. If testnet data reveals no material issues between August 17 and August 20, the fork will execute as scheduled.
