Two days after successfully deploying the final version of the testnet, Ethereum Foundation researchers have officially announced the launch date of the next major upgrade of the Ethereum network – called Fusaka. According to the announcement at the All Core Devs meeting on Thursday, the upgrade will officially activate on the mainnet on December 3, 2025.
This is a milestone that the developer community has been anticipating since mid-September and marks one of the most significant developments for Ethereum since the “Pectra” upgrade earlier this year. Fusaka has now completed the deployment on the Hoodi testnet, after successfully passing the testing phases on Holesky and Sepolia in early October.
Fusaka Upgrade – Dramatically Improved Speed, Security, and Scalability
Unlike other platform-changing Hard Fork , Fusaka is a backward-compatible upgrade that incorporates around 12 new EIP . The main goal is to enhance the sustainability, security, and scalability of both the main network and the currently thriving Layer 2 solutions.
One of the most notable is Peer Data Availability Sampling (PeerDAS), a technique that allows validators to access data faster and more efficiently. PeerDAS was Capital expected to be included in the February Pectra upgrade, but was delayed to ensure comprehensive testing.
Fusaka will also increase the Block gas Gas Limit from 30 million to 150 million units, opening up the ability to handle many times larger volume than the current one. According to experts, this will help double the blob capacity - an important factor in scaling the speed of the Ethereum network, especially as more decentralized applications (DApps) and decentralized finance (DeFi) protocols join.
$2 million security testing competition ahead of launch
To ensure the absolute security of the upgrade, the Ethereum Foundation launched a four-week audit contest, with a total prize value of up to $2 million for security researchers who discover bugs or potential vulnerabilities in Fusaka. This is one of the largest audit contests in Ethereum history, reflecting the organization's strong commitment to protecting user assets and data.
