The Ethereum developers have officially confirmed the launch date of the Fusaka hard fork on the mainnet — December 3, 2025. Before the update is implemented on the mainnet, Fusaka will be tested on several test networks throughout October.
This is reported by Business • Media
Fusaka Implementation Schedule and Key Milestones
As part of the preparation for this significant update, the Ethereum developers have outlined a phased launch of Fusaka on the test networks. According to the current schedule, the activation will take place:
- Holesky — October 1;
- Sepolia — October 14;
- Hoodi — October 28;
- Mainnet — December 3.
This was reported by analyst Kristin Kim following the weekly All Core Developers Consensus (ACDC) call #165.
“Important decisions were made during today’s Ethereum developers call, ACDC #165. The developers confirmed the schedule for launching public testnets and the BPO hard fork for Fusaka.”
Features of the Fusaka Update and Future Plans
The main change in Fusaka will be the gradual increase in throughput for so-called “blob” transactions. It is expected that in the first week after activation, the throughput will grow from 6/9 to 10/15, and by the second week — to 14/21. This will significantly enhance data processing efficiency in the Ethereum network and prepare it for future updates.
Fusaka will be the next major update following the Pectra hard fork, which was deployed in May 2025. Pectra included 11 improvement proposals (EIPs) and was described as the largest update since the Merge.
To ensure the security of Fusaka, the Ethereum Foundation announced a $2 million bounty competition for auditors on the Sherlock platform on September 15. Participants are tasked with finding potential vulnerabilities in the code within four weeks before the update is launched on the mainnet.
Changes to the testing infrastructure are also ongoing. At the beginning of September, a reminder was issued regarding the upcoming closure of the Holesky testnet — its support will be discontinued two weeks after the implementation of Fusaka. This decision was made following technical difficulties encountered during the deployment of Pectra.
It is expected that the gradual increase in blob throughput introduced by Fusaka will serve as the foundation for subsequent updates, including the large-scale release of Glamsterdam, scheduled for 2026. Thus, Ethereum continues its strategy to enhance the scalability and security of the network, laying the groundwork for further technological improvements.