How The Fusaka Upgrade Fits Into Ethereum’s Long-term Roadmap

On Dec. 3, 2025, Ethereum will activate the Fusaka upgrade on mainnet, its second major hard fork of the year after Pectra in May.

Rollups now carry the bulk of Ethereum transactions and fee revenue, yet they are still constrained by how much data they can post back to the layer 1 and what it costs.

Fusaka is designed to relieve that pressure. Its headline feature, PeerDAS (peer data availability sampling), lets validators verify rollup blob data without downloading everything, cutting bandwidth and storage requirements while opening the door to much higher data throughput.

At the same time, blob-only parameter (BPO) forks, new gas and block-size limits and history expiry tweaks prepare the chain for repeated capacity increases instead of one-off jumps.

In this article, we will unpack what Fusaka changes, where it sits in the Surge, Verge and Purge roadmap, and what it could mean for users, rollups and the broader Ethereum ecosystem over the next few years.

Did you know? Fusaka’s name comes from two internal upgrade code names, Osaka (Execution Layer) and Fulu (Consensus Layer), merged into “Fusaka.”

The Merge (2022) shifted Ethereum from proof-of-work to proof-of-stake, cutting energy use by around 99.9%.

Shapella (2023) enabled staked Ether (ETH) withdrawals, turning a one-way staking system into a liquid one and attracting more validators.

Dencun (March 2024) introduced Ethereum Improvement Proposal (EIP) 4844 “blobs,” a cheaper, temporary data lane for rollups, also known as protodanksharding.

Pectra (May 2025) added EIP-7702 account abstraction features and revamped staking parameters like the 2,048-ETH validator cap.

Source: CoinTelegraph