Ethereum's 'Glamsterdam' Upgrade Targets October 6 for Sepolia Testnet Activation

The Ethereum core engineers have set October 6, 2026 at 13:53 UTC as a projected target for the "Glamsterdam" network update's activation on the Sepolia public testnet. This update combines several Ethereum Improvement Proposals (EIPs), including those connected to the Pectra upgrades, therefore advancing future mainnet enhancements. The scheduled update path calls for advancement over private devnets, then Sepolia, another testnet known as Hoodi, and at last the mainnet. The first public testnet fork in this sequence is the Sepolia testnet activation; dates for Hoodi and mainnet still need to be verified.

The exact activation on Sepolia is planned for epoch 351232, therefore matching the October 6th date. But this date is provisional and depends on the effective and consistent running of a private devnet, presently scheduled for September 14th's Devnet-11. Developers are highlighting that the October 6th date is a goal rather than a strict deadline. Any problems found during the devnet testing phase might cause Sepolia activation to be delayed, therefore highlighting the iterative and deliberate approach taken to introduce such major network upgrades.

Though the widely debated Q4 2026 timeframe is the mainnet debut, its realization depends on the effective and seamless implementation of the Sepolia and 'Hoodi' testnet forks as well as the readiness of several Ethereum client tools. The present plan considers the October 6th date a starting point that may be changed in response to results of continuous testing and development.