Fusaka Mainnet Announcement

The Ethereum Foundation has announced the Fusaka mainnet upgrade, scheduled for activation on December 3, 2025. Fusaka follows the Pectra upgrade earlier this year and represents a major step in Ethereum's scaling roadmap. It introduces PeerDAS (Peer Data Availability Sampling) to significantly increase blob throughput, alongside optimizations across execution and consensus layers. The upgrade is designed to improve L1 performance, reduce costs for layer 2 rollups, and enhance user experience, while also laying groundwork for future scalability and security improvements.

Key Features

PeerDAS (EIP-7594): Enables blob data availability sampling, scaling throughput without compromising security.
Blob Parameter Only (BPO) Forks: Config-only upgrades to safely raise blob targets and maximums (Dec 9, 2025 and Jan 7, 2026)
ModExp Optimization (EIP-7883 & EIP-7823): Adjusts gas costs and sets upper bounds for cryptographic operations.
Transaction Gas Limit Cap (EIP-7825): Caps per-transaction gas at 16,777,216 to prevent DoS risks.
Network Protocol Optimization (EIP-7642): Introduces eth/69, streamlining sync and removing legacy fields.
Gas Limit Increase (EIP-7935): Raises default L1 gas limit to 60M.
UX Improvements: Adds secp256r1 precompile (EIP-7951) for hardware integration and CLZ opcode (EIP-7939) for efficient bit-counting.

Why It Matters?

Fusaka is a pivotal upgrade that scales Ethereum's blob capacity, strengthens L1 performance, and improves developer and user experience, while setting the stage for future scalability.