Ethereum upgrade Fusaka officially launched, Blob capacity has doubled

Ethereum’s Fusaka upgrade was officially launched on the mainnet on December 3, 2025. This Ethereum upgrade aims for comprehensive optimization of scalability and network efficiency through a series of backend innovations to strengthen Ethereum’s competitiveness in decentralized applications, while ensuring backward compatibility and network stability.

The upgrade integrates 11 Ethereum Improvement Proposals (EIPs), focusing on core protocol functionalities such as data availability, fuel efficiency, and network resilience. Notably, this upgrade does not involve any changes to smart contracts and is purely a backend technical evolution.

Three-Phase Blob Capacity Expansion Successfully Completed

One of the key achievements of the Ethereum upgrade is the three-phase expansion plan for Blob data capacity. After the mainnet upgrade, Blob capacity increases are carried out in two stages: the first phase was completed on December 17, 2025, and the second phase was implemented on January 7, 2026. According to Ethereum researcher Christine D. Kim, both hard forks for Blob capacity increased the current capacity by more than double.

Since the Dencun upgrade went live, Blob applications have shown steady growth. Data tracking from Dune Analytics indicates that the average number of Blobs per block has risen from 0.9 in March 2023 to the current 5.1, reflecting the vigorous development of the Layer 2 ecosystem. The doubling of capacity lays a solid foundation for further scalability.

PeerDAS Technology Drives Node Efficiency Innovation

A technological highlight of this Ethereum upgrade is the introduction of PeerDAS (Peer Data Availability Sampling). This innovative technology aims to optimize data availability by reducing node storage and bandwidth requirements by approximately 50%, thereby enhancing Layer 2 scalability.

Deploying PeerDAS significantly lowers hardware costs for node operators and further reduces the barriers to participating in network maintenance. This increased decentralization is particularly crucial for maintaining Ethereum’s long-term network security and resistance to censorship.

A New Engine Accelerating Layer 2 Ecosystem Growth

This Ethereum upgrade is expected to significantly improve Layer 2 transaction throughput through optimized transaction processing and reduced validator costs, ultimately lowering transaction fees for end users. For Layer 2 solutions like Arbitrum and Optimism, the scope for cost optimization further expands, promising a better user experience.

The combination of Blob capacity doubling and PeerDAS technology creates a “capacity + efficiency” dual-driven pattern. This will substantially reduce costs in scenarios such as high-frequency trading, bulk NFT operations, and cross-chain interactions.

Institutional Adoption and DeFi Competitiveness Enhancement

Another strategic significance of the Ethereum upgrade is supporting the adoption of institutional-grade applications. By addressing scalability and security gaps, improved regulatory clarity is expected to attract more trust and participation from traditional financial institutions.

In the DeFi ecosystem, cost reductions will enable the realization of more complex financial products, such as high-frequency market making, leveraged trading, and derivatives trading, making them more economically feasible. This not only reinforces Ethereum’s leading position in decentralized finance but also creates new application opportunities within the ecosystem.

During the upgrade process, the development team carefully excluded proposals like EIP-7907 (doubling contract code size limits) and EVM Object Format (EOF) upgrades to simplify the upgrade process and prioritize key features like PeerDAS. This pragmatic approach reflects sound engineering judgment.

Future-Oriented Network Resilience

The Ethereum upgrade involved extensive testing phases, including validation on multiple development networks, public testnets, and in-depth reviews by security auditing firms, ensuring thorough preparation before mainnet launch. Validators and node operators have also completed client software updates as required.

Fusaka represents a critical step in Ethereum’s evolution, with scalability and efficiency as core objectives. The achievements of this current phase of the Ethereum upgrade lay a solid foundation for widespread adoption in decentralized applications, DeFi, and institutional finance, while maintaining commitments to backward compatibility and network stability.