Ethereum has officially activated the Fusaka hard fork, an enhancement aimed at improving data availability and scalability across the ecosystem. This upgrade, the second major one of 2025 following the Pectra upgrade, is set to transform transaction throughput on the network.

Data and Performance Upgrades

The Fusaka upgrade is scheduled to launch at 21:49 UTC, incorporating Peer Data Availability Sampling (PeerDAS). This feature escalates the network’s capacity, permitting up to 8 times the throughput for Layer 2 rollups and resulting in lower transaction fees.

Tomorrow: Fusaka
Ethereum’s second major upgrade this year.
→ Feature highlight: PeerDAS – Unlocking up to 8x data throughput. For rollups, this means cheaper blob fees and more space to grow.
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Ethereum Twitter Post
— Ethereum (@ethereum) December 2, 2025

This innovative feature allows validators to verify only small, randomly chosen portions of data, which can lessen bandwidth needs by almost 85%. With Layer 2 networks benefitting from this upgrade, a 40–60% reduction in transaction fees is projected, contingent on overall chain activity.

The Fusaka update also raises the block gas limit from 30 million to 150 million units, facilitating greater transaction capacity per block. This should support lower costs and enhance overall performance for decentralized applications.

Future Improvements

Following the successful deployment on testnets like Hoodi, Sepolia, and Holesky, Fusaka prepares Ethereum for even broader scalability as it aims for Osaka, the next upgrade anticipated in 2026. This future upgrade is expected to introduce blob streaming enhancements and stateless validator clients.

With Layer 2 solutions like Arbitrum, Optimism, and Base preparing to implement PeerDAS, users can anticipate improved performance and lower costs moving ahead.