Ethereum’s next major network upgrade, Glamsterdam, activated on the Sepolia test network on October 6, 2026 at roughly 13:53 UTC, according to Cointelegraph and Crypto Briefing. The fork bundles enshrined proposer-builder separation and block-level access lists, and serves as one of the last rehearsals before a mainnet launch that still has no confirmed date.
What happened on Sepolia?
Cointelegraph reported that Glamsterdam went live on Sepolia at 1:53 pm UTC, citing an X post from Ethereum community contributor Pooja Ranjan. Crypto Briefing put the activation more precisely at 13:53:36 UTC, at epoch 353,024. Sepolia is the first public testnet to run the upgrade, and Crypto Briefing noted that earlier trials took place on internal environments including Plataberget and Devnet 8, with client team Prysm shipping a last-minute 7.2.1 patch before the fork. Developers describe the Sepolia run as a dress rehearsal that lets node operators and client teams surface bugs before the changes reach real value on mainnet.
The timeline had slipped before this. Reporting ahead of the fork noted that the Sepolia target had moved from an earlier August date after test-network bugs, making October 6 the rescheduled attempt, and other coverage noted the upgrade had already been pushed back more than once. Crypto.news, citing community contributor Pooja Ranjan, described the activation as putting changes to block production, parallel processing and gas pricing through a public network test. Ethereum developers have framed Glamsterdam as part of an accelerated release cadence following the Fusaka upgrade that reached mainnet in late 2025.
What is enshrined proposer-builder separation?
The headline change is EIP-7732, known as enshrined proposer-builder separation, or ePBS. Today, the split between the validator that proposes a block and the specialized builder that assembles its contents is handled by optional off-chain software such as MEV-Boost. According to Crypto Briefing and infrastructure firm Alchemy, EIP-7732 moves that separation into the protocol itself. Builders gain an on-chain identity and submit signed bids, and a new Payload Timeliness Committee of validators checks whether the winning builder delivered its block contents on time. Alchemy notes the design also widens the data-propagation window from roughly two seconds to about nine seconds and separates consensus validation from execution validation, giving validators more time to verify execution payloads. By baking the proposer-builder split into the protocol, the change is meant to reduce the network’s reliance on a small set of trusted off-chain relays, a long-standing concern for Ethereum’s censorship resistance and decentralization.
What are block-level access lists?
Glamsterdam also ships EIP-7928, or block-level access lists (BALs). Cointelegraph explained that BALs record the accounts and storage locations accessed within a block, which lets clients read state, validate transactions and compute state roots more efficiently and in parallel. The upgrade additionally includes gas-repricing changes that, in Cointelegraph’s description, better reflect the real cost of execution. Internally, the two halves of the fork carry the names Amsterdam on the execution layer and Gloas on the consensus layer, per Crypto Briefing. Together, the changes are aimed at hardening and scaling Ethereum’s base layer rather than at any single application.
Why does the 200 million gas limit matter?
One closely watched element on Sepolia is a much higher block capacity. Crypto Briefing reported that validators can opt in to raise the gas limit to 200 million, up from a prior ceiling of roughly 60 million, though it stressed the figure is a test target, not a promise. Cointelegraph framed the same number as a 200 million gas-limit floor that Glamsterdam establishes compared with the current limit of about 60 million. A higher gas limit would let the network process more transactions and computation per block, but Crypto Briefing said final mainnet gas-limit parameters have not been decided and there are no immediate mainnet changes. Alchemy cautioned that the repricing cuts both ways: contract deployments and other storage-heavy writes now cost more gas under the new model, a trade-off meant to better align fees with the long-term cost of state growth.
When will Glamsterdam reach mainnet?
No mainnet date is set. Cointelegraph reported that developers will first choose an activation date on the Hoodi testnet before scheduling the mainnet fork. Alchemy similarly said Hoodi and mainnet activation dates are not yet locked, though separate coverage pointed to a broad fourth-quarter 2026 mainnet target and pencilled in a tentative late-October Hoodi run, a date that appeared in only a single report and should be treated as unconfirmed. Coverage ahead of the Sepolia run also flagged a cautionary note from developers about a possible attack vector involving bad actors creating fake builder identities, a scenario the testnet phase is intended to probe before the rules go live with real stake behind them.
What should users and node operators do?
For ordinary ETH holders, the testnet activation requires no action. Alchemy noted that Glamsterdam touches both the execution and consensus layers, so every node operator will eventually need to update both their execution and consensus clients, and that some clients do not adopt the higher gas limit automatically, meaning operators must set it themselves before the fork. This article is informational and does not contain trading or investment advice. The testnet outcome, including how the network behaves under the higher gas target and the new block-building rules, will shape whether and when the changes are judged ready for Ethereum mainnet.
Sources
Cointelegraph – Ethereum’s Glamsterdam upgrade launches on Sepolia testnet (Oct 6, 2026)
Crypto Briefing – Ethereum’s Sepolia testnet activates Glamsterdam with optional 200 million gas limit (Oct 6, 2026)
Crypto.news – Ethereum Glamsterdam hits Sepolia with 200 million gas limit test
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Sarah Williams is STnews's Blockchain Editor, leading coverage of blockchain technology, DeFi investigations, exchange analysis and crypto regulation. Her reporting adheres to STnews's editorial standards — primary-sourced, cited, and non-advisory.
Conflicts of interest
I hold no positions in any cryptocurrency mentioned in my coverage. All investment-related content is reviewed by senior editors before publication. I am not compensated by any project I cover.
