What is the Fusaka Upgrade? Ethereum’s Biggest Scaling Bet Yet

The Fusaka upgrade, set for Q4 2025, aims to enhance Ethereum's data capacity, security, and developer utilities significantly. It will increase blob throughput by eight times through a process called PeerDAS, which allows nodes to sample data instead of storing every piece of data permanently. This upgrade is designed to manage rising demands for layer 2 transactions without straining node operators. To help structure blob management, it introduces a reserve fee system and parameter-only forks for quick adjustments in response to demand. Fusaka will also implement safeguards to prevent denial-of-service attacks, with measures such as caps on the size of input operations and execution blocks. Additionally, the upgrade includes enhancements for user experience, like preconfirmation support for transactions, and more tools for developers, including native P-256 signature verification. Users will not need to take action during the transition, but validators must update their clients for the change to take effect. The rollout includes a series of upgrades across multiple testnets leading up to the mainnet in December 2025.

Source 🔗