Ethereum core developers have set December 3 as the activation date for the Fusaka upgrade, representing a significant milestone in the network’s evolution aimed at improving scalability and reducing transaction costs. The upgrade marks the next step in Ethereum’s ongoing commitment to enhance its infrastructure.
Prior to this mainnet activation, the Fusaka upgrade will undergo extensive testing on networks including Holesky, Sepolia, and Hoodi throughout October. This phased approach ensures that developers can fine-tune the upgrade and address any potential issues before wide-scale implementation.
To further enhance security, the Ethereum Foundation initiated a $2 million Fusaka audit contest on September 15. Co-sponsored by Gnosis and Lido and hosted on the Sherlock platform, this contest encourages participants to identify vulnerabilities in the upgrade’s code and will run for a duration of four weeks. This proactive measure highlights the community’s commitment to ensuring the robustness of the upgrade before its launch.
The decision to activate Fusaka in December aligns with dialogues from the recent All Core Developers Consensus (ACDC) Call #165, where it was determined that the upgrade could not go live any earlier than 30 days following the Hoodi testnet fork.
One of the key features of the Fusaka upgrade is the introduction of Peer Data Availability Sampling (PeerDAS) via Ethereum Improvement Proposal (EIP) 7594. This innovative mechanism allows nodes to validate only segments of large data blobs rather than requiring the entire dataset, effectively reducing bandwidth demands and enhancing storage scalability, which is critical for regional layer-2 rollup operations.
Current data from Blockworks Research indicates that blob utilization has surpassed 90% for leading rollups, with figures showing Arbitrum One operating at 99.6% capacity and OP Mainnet at 99.2%. Median blob fees are reported to be between $0.49 and $3.05 per MiB, underscoring the urgent need for enhancements to capacity. The Fusaka upgrade aims to alleviate this congestion through two planned Blob Parameter Only (BPO) forks that will follow the mainnet activation. The first is expected around December 17, which will increase the maximum number of blobs from 9 to 15. A subsequent fork scheduled for January 7, 2026, will further raise the limit to 21. These BPO forks are designed to adjust blob parameters seamlessly without necessitating client updates, as noted by Ethereum researcher Christine Kim.
As the Ethereum community prepares for this important upgrade, developers and users alike are poised to benefit from improved efficiency and reduced costs, setting the stage for further advancements in blockchain technology. This story is expected to evolve as more information becomes available.
