Ethereum’s Fusaka upgrade hits final testnet on Hoodi before mainnet launch

Ethereum’s Fusaka upgrade has gone live on the network’s final testnet, Hoodi, as developers prepare for the mainnet launch slated for December.

Summary

• Ethereum’s Fusaka upgrade was successfully activated on the Hoodi testnet on Oct. 29.
• Fusaka’s phased mainnet rollout is scheduled to begin on Dec. 3.

According to the team at Nethermind, an Ethereum execution client, the Hoodi Fork was “successfully completed” on Oct. 28, marking a “key milestone on the road to Fusaka.”

Despite a successful launch, Ether (ETH) saw little movement and fell over 2% to trade around the $4,000 mark. Traders remained cautious amid macro uncertainty as the Federal Open Market Committee meeting kicked off on the same day, which would culminate in a decision on interest rates. Risk assets like ETH often see volatility around interest rate decisions.

Ethereum edges closer to Fusaka

Hoodi is the final testnet phase before the mainnet launch of Fusaka, and the activation comes after successful deployments on Sepolia and Holesky testnets earlier this month. Sepolia was upgraded on Oct. 14, prior to which Holesky had been activated for testing on Oct. 1 before being formally decommissioned following the successful execution.

Ethereum’s Fusaka upgrade is a direct successor to the Pectra upgrade, which went live on the mainnet in early May.

Pectra introduced a number of changes, such as streamlined validator operations, account abstraction via EIP-7702, and a moderate increase in blob capacity per block, which helped reduce Layer-2 transaction costs and improve data throughput.

Blobs are binary large objects that allow Layer-2 rollups to post data more efficiently onto Ethereum, thereby helping lower fees and scale the network without compromising its core consensus.

Fusaka will increase Ethereum’s blob capacity

For the Fusaka upgrade, developers plan to introduce Blob Parameter Only (BPO) forks, which are expected to gradually raise the network’s blob capacity through two targeted follow-up hard forks.

Among other key changes, Fusaka will bring Peer Data Availability Sampling via EIP-7594 to improve how nodes access Layer-2 data, the introduction of Verkle Trees for more compact state proofs, and an increased block gas limit that is expected to improve throughput on the base layer.

Fusaka will be rolled out in three stages, beginning with the mainnet activation scheduled for Dec. 3, which will introduce the core protocol changes, including PeerDAS, Verkle Trees, and the updated gas parameters. 

This will be followed by the first Blob Parameter Only fork around Dec. 17, which will increase the number of blobs per block to 10 with a maximum of 15.  A second fork is tentatively planned for Jan. 7, 2026, which will further raise the blob count to 14 with a maximum of 21, more than doubling the network’s current data capacity and setting the stage for improved scalability across Layer-2 ecosystems.