Ethereum’s Fusaka Update: Is It Possible to Achieve Both Scalability and Decentralization?

The Fusaka upgrade for Ethereum, expected to go live on the mainnet towards the end of 2025, has captured considerable interest as the blockchain ecosystem gears up for a major leap in network scalability. As a crucial milestone in Ethereum’s roadmap to boost efficiency and scalability, this upgrade incorporates 11

Improvement Proposals (EIPs) that aim to improve data accessibility, strengthen node reliability, and enhance transaction capacity. These updates are intended to meet the increasing requirements of the network, especially from layer 2 (L2) solutions and decentralized finance (DeFi) applications, all while safeguarding decentralization and network security. The Fusaka upgrade is set to build on earlier advancements, such as the Pectra hard fork in May 2025, which increased staking thresholds and rolled out account abstraction features.

One of Fusaka’s main breakthroughs is , a solution crafted to decrease the computational and storage load on network nodes. PeerDAS allows nodes to check only part of the data in each block, letting Ethereum expand the number of blobs per block—a vital upgrade for L2 rollups—without demanding every node keep a complete record. This method could theoretically boost the network’s blob capacity by up to eight times per block, which is vital for lowering transaction expenses and improving the efficiency of L2s. Alongside this, will permit gradual modifications to blob limits without full-scale network updates, allowing the system to quickly respond to shifting L2 requirements.

Another significant aspect of Fusaka is the planned increase in the block gas limit, which will be raised from 30 million to 150 million units—a fivefold jump—to support greater transaction throughput. This change, together with updated gas pricing for cryptographic functions like modular exponentiation (MODEXP), is designed to alleviate congestion and make fee allocation more equitable. For example, EIP-7918 will link blob fee calculations to execution costs, preventing situations where fees drop to almost nothing during periods of low activity. These measures should help stabilize gas fees and give both users and developers more predictable costs.

The upgrade is undergoing validation on multiple public testnets, including Holesky, Sepolia, and Hoodi, with a mainnet rollout slated for December 3, 2025. Developers are taking a gradual approach to deployment to reduce risks, planning further hard forks in December 2025 and January 2026 to incrementally raise blob capacity from 6 to 48 blobs per block. To underscore the critical nature of this upgrade, the Ethereum Foundation has introduced a $2 million bug bounty program to encourage comprehensive security reviews.

The implications of Fusaka reach well past technical refinements. By making Ethereum more scalable, the upgrade is projected to enhance its standing against newer blockchains like

and Chain, which are noted for their rapid transactions and minimal fees. Experts believe Fusaka might rekindle investor enthusiasm for Ethereum, particularly as exchange-traded funds (ETFs) for and Ethereum attract attention and the market looks for scalable, reliable blockchain infrastructure. The upgrade also resonates with larger industry movements, such as the rising use of L2 solutions and the continued expansion of DeFi, both of which depend on efficient data processing and affordable transactions.

Still, there are obstacles ahead. Increased block size and higher gas limits could put extra pressure on smaller validators, potentially making network participation more centralized. In addition, the shift to PeerDAS and BPO forks will require close cooperation among client development teams to avoid fragmentation. Developers are carefully assessing these challenges, with further enhancements anticipated in the 2026 Glamsterdam upgrade, which will concentrate on shortening block times and adding advanced EVM functionalities.