Ethereum Developers Set Fusaka Hard Fork Date for December 3, 2025

Ethereum developers have confirmed the schedule for the Fusaka update, which is set to activate on the mainnet on December 3, 2025. This was reported by analyst Christine Kim after the weekly All Core Developers Consensus (ACDC) call #165.

According to the approved plan, the update will go through several test phases:

• Holesky — October 1;
• Sepolia — October 14;
• Hoodi — October 28;
• Mainnet — December 3.

Developers also clarified that blob throughput will gradually increase:

• in the first week — from 6/9 to 10/15;
• in the second — to 14/21.

Fusaka will be the next significant Ethereum hard fork after Pectra, which was activated on May 7, 2025. At that time, 11 improvement proposals (EIP) were implemented, and the update was called the largest since the Merge.

The Ethereum Foundation has already begun preparations for the new release. On September 15, the organization launched an auditor competition on the Sherlock platform with a prize pool of $2 million, aimed at finding vulnerabilities in the Fusaka code. The competition will last four weeks.

Additionally, changes are occurring in the Ethereum ecosystem at the test network level. In early September, the Foundation announced that support for Holesky would be discontinued two weeks after Fusaka’s deployment. The decision is related to technical difficulties encountered during the Pectra deployment.