Ethereum is still targeting October 6 at 1:53 p.m. UTC to activate Glamsterdam on the Sepolia testnet. The date now appears as the next milestone on Ethereum’s official roadmap. But it remains fragile: Glamsterdam has not yet achieved any complete passage on a stable private devnet, and several bugs must be corrected before exposing the update to Sepolia. The mainnet remains scheduled for the fourth quarter of 2026, with no confirmed date.
In brief
- Glamsterdam are targeting Sepolia on October 6, but the date remains conditional.
- Devnet-9 has 1000 validators and still can’t finalize properly.
- A bug related to EIP-8037 forces execution layer clients to modify their code.
Devnet-9 still blocks before passing to Sepolia
Glamsterdam needed to use devnets to eliminate these kinds of problems before reaching public networks. Tremplin.io was already following Glamsterdam’s entry into its advanced testing phase in the spring.
Five months later, the tests are much heavier. Glamsterdam-Devnet-9 launched on September 1 with 1,000 validator nodes, the largest Glamsterdam devnet so far by number of nodes. The result is not yet as expected: the network does not finalize correctly. Too few validators offer and attest to the same head of chain to achieve the purpose.
Stefan Starflinger, DevOps engineer at the Ethereum Foundation, believes that this size mainly made it possible to highlight borderline cases that would pass less easily on smaller configurations.
Devnet-8 had already encountered a more serious problem. A bug could cause the network to freeze when a validator proposed a block sharing the same parent hash as that expected in a specific situation. Customer teams have since worked on fixes. It is therefore not Sepolia which is dysfunctional. Glamsterdam hasn’t gotten there yet.
EIP-8037 adds a new problem to solve
Another bug directly affects EIP-8037, one of the important proposals of Glamsterdam. This EIP changes the pricing for creating new permanent data on Ethereum. The network wants to increase its capacity without letting its database grow at the same rate. EIP-8037 notably introduces separate accounting for certain costs linked to state creation.
Tremplin.io had already explained why this adjustment matters in the project aimed at strongly increasing the execution capacity of Ethereum.
Maria Silva, a researcher at the Ethereum Foundation, identified a problem with this EIP during testing. The fix requires an update of all affected runtime clients.
Ethereum will therefore make a comeback. The developers are now preparing a new devnet before Sepolia. CryptoPotato reports that Devnet-11 has become the test to watch, with Devnet-10 no longer the primary milestone in the schedule reported this week.
Parithosh Jayanti, who chaired the developers’ meeting, did not guarantee October 6. If the next devnet still encounters significant issues, teams will need to re-evaluate the date on a “case by case” basis. October 6 is therefore indeed a target. Not a promise yet.
Ethereum: the mainnet remains targeted for the end of 2026, without confirmed date
Ethereum.org continues to show Q4 2026 for Glamsterdam deployment on the mainnet. No specific day is indicated. Sepolia officially appears as the next milestone with the date of October 6.
After Sepolia, Hoodi must still come, the second public testnet planned for the deployment. Here too, the developers preferred to wait before setting a date.
Enrico del Fante, of Consensys, notably pleaded for a few additional weeks before committing to Hoodi. The problems encountered on Devnet-9 make an overly precise schedule difficult to maintain.
The issue goes beyond a simple crypto hard fork. Glamsterdam must fundamentally change the way Ethereum builds and verifies its blocks. Its program includes ePBS, or integrated separation between block proposers and builders, as well as Block-Level Access Lists, designed to prepare for more parallel processing.
The network is already preparing for the sequel. Tremplin.io recently detailed the work planned after Glamsterdam around Hegotá and privacy. For now, December remains possible. But Ethereum first needs to get something much simpler on paper: a Glamsterdam devnet that finalizes cleanly. If Devnet-11 succeeds, October 6 will remain within range. Otherwise, Sepolia could still wait.
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