Ethereum developers are preparing for the second network upgrade of 2025 to go live on the blockchain’s mainnet on Wednesday.
Fusaka – a mix of the names Fulu + Osaka – consists of two upgrades performed simultaneously on the consensus and execution layers of Ethereum.
The goal of the upgrade is to enable Ethereum to handle the large transaction throughput of layer 2 chains that use blockchain as a base layer. Fusaka includes 12 code changes, also known as “Ethereum Improvement Proposals” (EIPs) that will make the Layer 2 experience faster and cheaper.
The most significant change to Fusaka is known as PeerDAS, which allows validators to verify only segments of data instead of entire “blobs”, easing the bandwidth demand and reducing the expense of validators and Layer 2 networks. Layer 2s currently submit thousands of transactions to Ethereum via “blobs”, where validators currently on the Ethereum blockchain must download all transaction data from the blob to verify its correctness, creating bottlenecks. With this improvement, these validators will only need to verify a fraction of a blob, thereby speeding up the process and reducing the transaction fees that accompany it.
Fusaka not only improves the layer 2 experience, but also introduces improvements that also affect Ethereum itself, although they are much more minor. The changes include the maximum size of a single transaction, aimed at strengthening security, as well as new code aimed at making smart contracts more efficient.
Establishments are also increasingly paying attention to this upgrade. Earlier this month, Fidelity Digital Assets released a report claiming that Fusaka represents a decisive shift towards a more strategically aligned and economically coherent roadmap.
Read more: Ethereum Developers Lock Fusaka Upgrade for December 3 with PeerDAS Rollout
