Ethereum’s Fusaka update enhances the foundational layer, paving the way for further expansion of decentralized applications

Ethereum’s forthcoming Fusaka upgrade, planned to go live on the mainnet on December 3, 2025, aims to greatly improve network scalability and cut costs for Layer 2 (L2) rollups. This upgrade will gradually increase blob capacity—the

units essential to L2 protocols—while also introducing Peer Data Availability Sampling (PeerDAS) through EIP-7594. This measure seeks to streamline node performance and enhance how data is verified. Developers have mapped out a careful deployment schedule, starting with Holesky testnet on October 1, then moving to Sepolia and Hoodi, to thoroughly test stability before the mainnet launch.

Fusaka’s main goal is to boost Ethereum’s data throughput to support the increasing use of L2s. Blob capacity is set to rise from the existing 6/9 target/max to 10/15 blobs per block on December 17, 2025, and then to 14/21 blobs by January 7, 2026. This substantial increase is anticipated to lower transaction expenses for L2 users and provide greater throughput for data-intensive applications, including rollups and decentralized finance (DeFi) platforms. The staged upgrade process, called Blob Parameter Only (BPO) forks, allows for step-by-step enhancements without needing to overhaul client software, reducing disruption for both node operators and developers.

One of Fusaka’s standout features, PeerDAS, will lessen bandwidth and storage requirements for validator nodes by enabling data availability checks through sampling rather than downloading entire blobs. This approach reduces operational costs and may foster greater network decentralization by making it easier for smaller operators to run nodes. This aligns with Ethereum’s broader goal of reinforcing its foundational layer as a scalable settlement platform while promoting L2 growth.

The Fusaka upgrade also has notable economic effects. By increasing blob throughput and refining data management, the changes are designed to better match Ethereum’s revenue streams with its function as a settlement layer. Developers are considering proposals like EIP-7623 and EIP-7762 to modify incentives for blob utilization, addressing concerns that high levels of usage (close to 80%) currently don’t translate into greater revenue for Ethereum’s base layer. Additionally, EIP-7918 is set to introduce capped base fees for blob transactions, which will create more predictable costs for applications requiring extensive data and bring more stability to the network’s fee model.

Fusaka continues the work of previous improvements, such as the Pectra hard fork in May 2025, which made staking more efficient and advanced account abstraction. It also follows the Dencun upgrade (2024), which first brought blobs into the network to cut L2 costs. With the validator exit queue now at a record 2.6 million ETH, the

community remains committed to maintaining a balance between scalability and security. Co-founder Vitalik Buterin has underscored that longer exit periods are crucial for the network’s resilience, despite worries about increased selling pressure from withdrawn ETH.

If Fusaka succeeds, Ethereum could eventually process up to 2,000 transactions per second, in line with proposals like EIP-9698, which imagines a 100-fold increase to the gas limit. This direction supports Ethereum’s ambition to serve as the base layer for decentralized applications while tackling concerns about fragmentation across L2s. The upgrade’s focus on infrastructure, together with ongoing projects like the Open Intents Framework, is intended to harmonize cross-chain operations and address the risks posed by expanding multichain usage.