Points of Focus 

• Fusaka activates PeerDAS, expanding blob capacity to cut L2 costs and enable 100k+ TPS.  
• Includes gas limit hike to 60M, blob fee minimum, and passkey signature support.  
• Smooth mainnet rollout; BPO forks set for December 9 and January 7 to further scale data.

Ethereum’s mainnet successfully activated the Fusaka hard fork at 21:49 UTC on December 3, deploying PeerDAS to dramatically expand data availability for Layer 2 rollups. The upgrade also introduces a suite of tweaks, paving the way for 100,000+ transactions per second across the ecosystem.

The Fusaka upgrade is today.

Ethereum is securely scaling. pic.twitter.com/YaJ5WL4tSc

— Ethereum (@ethereum) December 3, 2025

What is the Fusaka upgrade, and how does it work?

Fusaka, which is Ethereum’s second major upgrade of 2025 after Pectra, bundles 12 Ethereum Improvement Proposals with a renewed focus on scalability and efficiency. The headline feature, EIP-7594 (PeerDAS), lets validators sample only portions of blob data instead of downloading entire blocks, slashing bandwidth needs by up to 90% and enabling blob throughput to grow from between 6 – 9 per block to 14 – 21 via planned “Blob Parameter Only” forks on December 9 and January 7. 

This builds on the progress made with Dencun’s blob introduction in March 2024, which cut L2 fees by 90-95%, by making data storage cheaper and more sustainable for rollups like Arbitrum and Optimism.

Other changes include EIP-7918, which sets a minimum blob base fee to stabilize economics during low-activity periods; EIP-7951, adding a secp256r1 precompile for efficient signature verification in passkey-based wallets; and EIP-7892, allowing interim blob capacity increases without full hard forks. The upgrade also doubles the default block gas limit from 30 million to 60 million, boosting L1 throughput while adding safeguards like block size caps (EIP-7934) to prevent overloads.

Reactions to the upgrade

The rollout finalized smoothly after 15 minutes, with no reported issues on the EthStaker livestream where core developers gathered to monitor. Bitwise Asset Management called Ethereum’s Fusaka upgrade a foundational step that solidifies the network’s position as the go-to settlement layer for institutional on-chain finance, thanks to a new minimum blob base fee that ensures steady revenue even during quiet periods.

Bitwise CIO Matt Hougan described Fusaka as the kind of “unflashy infrastructure change” markets overlook at first but credit later for making the network more investable. Analyst Max Shannon added that it avoids dramatic fee spikes during inelastic markets, projecting doubled L1 capacity over a year via the 60 million gas limit hike and PeerDAS bandwidth cuts of up to 85%.

Vitalik Buterin, who has been vocal about Ethereum’s privacy moves in recent times, hailed the Fusaka upgrade as a breakthrough realization of sharding. Writing on X, he stated that PeerDAS in Fusaka enables consensus on full blocks where no single node needs to process more than a tiny data fraction, using robust client-side probabilistic checks that even withstand 51% attacks.

PeerDAS in Fusaka is significant because it literally is sharding.

Ethereum is coming to consensus on blocks without requiring any single node to see more than a tiny fraction of the data. And this is robust to 51% attacks – it's client-side probabilistic verification, not… pic.twitter.com/OK81xBteER

— vitalik.eth (@VitalikButerin) December 3, 2025

User Terence Chain was full of praise for the Ethereum team, “L1s and L2s running as one well-oiled machine that moves forward together.”

Fusaka went well, and L2s posting blobs without missing a beat. Credit to all the teams. L1 and L2s running as one well-oiled machine that moves forward together pic.twitter.com/QoWbarFrcJ

— terence (@terencechain) December 3, 2025

For L2 builders, Fusaka accelerates the modular scaling bet, with five-figure TPS already in sight on testnets. Ethereum traded at $2,927 on December 4, up 1.05% as markets digested the news.