Ethereum upgrades to Fusaka today, cutting rollup data cost

Ethereum is set to activate its Fusaka hard fork on mainnet later today, merging the Osaka execution-layer upgrade with the Fulu consensus-layer update. Activation is planned at a scheduled block height and will roll out across execution and consensus clients. The release introduces Peer Data Availability Sampling, or PeerDAS, and is the network’s second major upgrade of 2025 after May’s Pectra fork.

PeerDAS changes how blob data is stored and checked across the network. Instead of each node holding full blob payloads, nodes keep one-eighth of the data and verify availability by sampling pieces from peers. The design is intended to expand data capacity for rollups while cutting storage and bandwidth demands, with a target of up to 8x theoretical data throughput for Layer 2 systems.

The upgrade increases blob capacity and adjusts fee mechanics to support higher transaction volumes. EIP-7918 revises blob fee pricing to better reflect network congestion, and the protocol now caps single-transaction gas usage at 16,777,216 (2^24) gas units to limit denial‑of‑service risk from oversized transactions.

Fusaka introduces blob-parameter-only forks, allowing changes to blob capacity targets and limits without a full hard fork. This gives developers a way to tune throughput based on rollup demand while maintaining network stability.

The release adds native support for secp256r1 signatures, enabling passkey-style authentication compatible with Apple Secure Enclave and Android Keystore. The feature is designed to support hardware-backed sign-in and account recovery without seed phrases.

In an official announcement, Ethereum described Fusaka as the network’s second major upgrade this year and highlighted PeerDAS as “unlocking up to 8x data throughput. For rollups, this means cheaper blob fees and more space to grow.”

Sharplink CEO Joseph Charom called Fusaka “a massive milestone for Ethereum and its institutional adoption journey.”

Fusaka follows the Pectra fork, which combined the Prague and Electra upgrades and introduced changes to validator operations and account functionality. After Pectra, ETH gained 29% during the ensuing period, though Fusaka centers on data availability and throughput rather than staking and account features.