Ethereum Fusaka Upgrade: What It Is and Why It Matters

Key Points

The Ethereum Fusaka upgrade, a major hard fork scheduled for the near future, will dramatically improve Ethereum’s scalability, performance, and cost efficiency—especially for Layer 2 solutions like Arbitrum and zkSync. With innovations such as PeerDAS, Verkle Trees, a 150 million gas limit, and a suite of new EIPs, Fusaka will accelerate transactions, lower fees, and make decentralized node operations more accessible.

Users will experience cheaper and faster dApp interactions; developers gain new tools for building advanced applications; validators benefit from lower hardware requirements. While ETH price may fluctuate, Fusaka solidifies Ethereum’s leadership and sets the stage for future upgrades like Glamsterdam.

The Fusaka upgrade marks a major milestone for the Ethereum network—also known as a hard fork—planned for Q4. Its primary goals are to scale up throughput, decrease costs, and boost efficiency, particularly for Layer 2 solutions such as Arbitrum and zkSync. "Fusaka" combines Fulu (representing consensus) and Osaka (representing execution), building on advances from The Merge and Dencun to move Ethereum closer to massive transaction volumes while preserving decentralization and security.

What Is the Ethereum Fusaka Upgrade?

Fusaka is a significant hard fork, encompassing 12 Ethereum Improvement Proposals (EIPs) to upgrade the network’s infrastructure. This is not just a routine update—it's a major leap in tackling Ethereum’s scalability and transaction cost issues.

Core objectives of the upgrade include:

• Higher transaction throughput: Enables far more transactions per second to meet rising ecosystem demand.
• Lower gas fees: Focuses on reducing costs for Layer 2 networks, making Ethereum more affordable for all users.
• Greater efficiency: Streamlines data processing and validator operations, while minimizing hardware requirements.
• Support for decentralization: Empowers individuals to run nodes at home without the need for specialized infrastructure, preserving Ethereum’s decentralization.

Fusaka has passed successful testing on Holesky, Sepolia, and Hoodi testnets. Importantly, the "final rehearsal" on Hoodi helped ensure a smooth and secure mainnet launch.

Key Features of the Fusaka Hard Fork

Fusaka introduces a wide range of transformative changes to the Ethereum ecosystem. Here are the core features explained:

1. PeerDAS: Accelerating Layer 2 Scalability

How it works: Peer Data Availability Sampling (PeerDAS), implemented in EIP-7594, brings a new method for validators to handle Layer 2 data. Rather than downloading the full "blob" (large data blocks for L2 rollups, introduced in Dencun), validators only verify small random segments from other nodes throughout the network.

This significantly reduces bandwidth and storage needs, optimizing overall system performance. The process is based on statistical sampling: by checking many small parts, validators can confidently verify the integrity of the entire blob.

Impact:

• Major L2 scaling: PeerDAS increases blobs per block from 12 to a target of 50, enabling Layer 2 solutions like Arbitrum, Optimism, and zkSync to reach tens of thousands of TPS, compared to just 15–30 TPS on Layer 1 today.
• Lower transaction fees: Reduced data costs directly translate to lower L2 fees, even during network congestion, making DeFi and NFT apps more accessible.
• Greater decentralization: Lower resource requirements mean validators can use consumer-grade hardware, furthering Ethereum’s commitment to openness and decentralization.

Significance: Vitalik Buterin describes PeerDAS as the "key" to Layer 2 scaling. This technology positions Ethereum as a robust global payment layer for applications such as international remittances and blockchain gaming, all while maintaining strong security.

2. Higher Gas Limit per Block: More, Faster Transactions

How it works: Fusaka raises the gas limit per block from 45 million to 150 million. Gas is the metric for computational effort required for transactions or smart contracts. A higher gas limit means each block can handle more complex operations, including advanced smart contracts for DEXs and lending protocols.

Impact:

• Greater throughput: Layer 1 TPS can rise from about 15–30 to 40–60, depending on transaction complexity, dramatically reducing confirmation wait times.
• Reduced congestion: Processing more transactions per block eases network bottlenecks, helping stabilize gas fees even during surges (such as hot NFT launches).
• Hardware considerations: While nodes may need modest upgrades, PeerDAS offsets bandwidth and storage needs, keeping node operation accessible to individual stakers.
• Layer 2 synergy: Larger block capacity lets Layer 2 rollups pack thousands of transactions into a single block, propelling ecosystem scalability.

Significance: A higher gas limit means faster, more stable transactions and provides critical momentum for Layer 2 development—essential for Ethereum’s scalable future without sacrificing decentralization.

3. Verkle Trees: Streamlined Data for the Community

How it works: Fusaka replaces the classic Merkle Tree structure with Verkle Trees—a more efficient method for organizing blockchain state (such as balances and smart contract data). Verkle Trees use polynomial vector commitments, yielding much smaller proofs and allowing quick, resource-saving verification.

Impact:

• Light client support: Low-powered devices like smartphones and IoT hardware can run light clients to verify the blockchain without downloading the full chain, broadening network participation.
• Reduced storage needs: Nodes require less disk space, lowering the barrier to running personal nodes and protecting network decentralization.
• Foundation for future upgrades: Verkle Trees pave the way for Danksharding—the next major upgrade aimed at boosting Ethereum’s data capacity and scalability.

Significance: Efficient data verification makes Ethereum more accessible and decentralized, setting the stage for widespread blockchain adoption.

4. Blob Parameter Only Forks: Flexible Scaling

How it works: EIP-7892 introduces Blob Parameter Only (BPO) hard forks, enabling gradual increases in blob capacity (for example, from 10 to 15, then 14 to 21 blobs per block) without overhauling the entire network. These changes will be rolled out after mainnet stability is achieved.

Impact:

• Adaptive scaling: BPO lets Ethereum adjust blob throughput based on actual Layer 2 usage, preventing overload during demand spikes (like DeFi booms).
• Layer 2 growth support: Higher blob capacity allows rollups to process more transactions, helping Layer 2 solutions scale alongside Ethereum.
• Network stability: Gradual upgrades reduce risks compared to major overhauls, ensuring dApps and user operations remain stable.

Significance: BPO offers a flexible mechanism to expand Ethereum’s data layer, supporting Layer 2 ecosystems like DeFi and blockchain gaming for the long term.

5. EVM and Security: Smarter, Safer Smart Contracts

How it works: Fusaka includes several EIPs to optimize the Ethereum Virtual Machine (EVM) and boost security:

• EIP-7823 and EIP-7883: Adjust gas pricing for ModExp (modular exponentiation) and limit input sizes, preventing DoS attacks and ensuring fair costs for cryptographic operations, especially zero-knowledge proofs.
• EIP-7910: Provides the eth_config tool, allowing node operators to reference fork schedules and configuration data directly, simplifying upgrades.
• EIP-7934: Sets a hard limit on block size (by bytes, not just gas) to stop malicious transactions from slowing the network.
• EIP-7951: Adds secp256r1 elliptic curve support, bringing Ethereum in line with Web2 security standards and compatibility with platforms like Apple Pay.

Impact:

• More efficient smart contracts: Gas optimization accelerates dApps and reduces costs for both developers and users.
• Strengthened security: Block size and ModExp limits defend against attacks, ensuring network reliability.
• Developer-friendly tools: eth_config streamlines node management, while secp256r1 support increases wallet choices for individuals and institutions.

Significance: These updates make Ethereum safer, more efficient, and easier to use, supporting continued growth in dApps and enterprise adoption.

6. Fee Market Upgrades: Stable Blob Fees

How it works: EIP-7918 introduces a floor for blob fees, preventing them from dropping too low (like 1 wei) during periods of low demand, ensuring a minimum cost for Layer 2 data.

Impact:

• Predictable costs: Layer 2 operators can plan expenses more easily, resulting in steadier user fees.
• Economic balance: Fee floors maintain validator incentives to process blobs, supporting network stability.
• Layer 2 innovation: Stable fees attract developers to build on Layer 2, driving progress in DeFi, NFTs, and decentralized social networks.

Significance: Fee market stability helps Fusaka build a durable economic model for Layer 2, making Ethereum more appealing to developers and users alike.

How Does Fusaka Affect You?

Fusaka’s changes impact every part of the ecosystem, with distinct benefits for different user groups:

Everyday Users

If you use Ethereum dApps like Uniswap, OpenSea, or Layer 2 solutions like Arbitrum, you’ll see major improvements:

• Much faster transaction confirmations
• Significantly lower transaction fees, especially on Layer 2
• More stable performance even during high-activity periods (like IDOs and airdrops)
• Less network congestion and fewer fee spikes

Developers and Builders

If you’re building dApps, Fusaka offers key advantages:

• Larger blob capacity for more data processing
• Optimized EVM for building advanced platforms like DEXs and prediction markets
• eth_config tool makes node management easier
• secp256r1 support expands wallet compatibility, making dApps more accessible

Validators and Node Operators

If you run nodes or stake ETH, Fusaka delivers notable improvements:

• PeerDAS and Verkle Trees reduce bandwidth and storage needs, cutting operational costs
• Though a higher gas limit may require slight hardware upgrades, overall requirements remain reasonable for individuals
• Lower resource barriers open up network participation to more users

Organizations and Enterprises

If you provide staking, custody, or use Ethereum for business:

• Lower Layer 2 costs for large-scale operations
• Enhanced security through ModExp and block size limits
• Standardized wallet compatibility makes integration with traditional finance easier

Traders

If you trade ETH or tokens on Ethereum:

• Improved trading environment thanks to the higher gas limit (from 45M to 150M)
• Layer 2 scaling via PeerDAS increases throughput and reduces congestion
• More stable gas fees, even in volatile markets
• High-frequency trading on Arbitrum and zkSync becomes cheaper, optimizing HFT strategies
• However, ETH price remains subject to macro factors—investors should monitor network performance and sentiment post-upgrade

Ultimately, Fusaka benefits every segment of the Ethereum ecosystem—from simple ETH transfers to building complex dApps, strengthening the network, supporting crypto businesses, and enabling professional trading.

Why Is Fusaka Critical for Ethereum’s Future?

Fusaka is a pivotal step in Ethereum’s scaling roadmap, delivering breakthrough improvements:

Massive Scalability

With PeerDAS and a higher gas limit, Layer 2 solutions can target up to 100,000 TPS, rivaling the fastest blockchains like Solana and Polygon. This enables support for global-scale applications, from cross-border payments to complex supply chains.

Significant Cost Reductions

Lower transaction fees benefit individual users and encourage Ethereum adoption in organizations. Reduced costs make daily payments and enterprise deployments on Ethereum more practical.

Commitment to Decentralization

Despite greater performance, Fusaka maintains a strong focus on decentralization. Thanks to PeerDAS and Verkle Trees, running a node remains accessible, preventing dominance by large entities.

Foundation for Future Upgrades

Fusaka isn’t just a standalone update—it’s the launchpad for future improvements like Glamsterdam. Upcoming upgrades will further separate block proposing and building (proposer-builder separation), speed up block times, and introduce additional features.

Strengthening Leadership

Fusaka’s upgrades reinforce Ethereum’s position as the top blockchain for decentralized applications and as the backbone of a global decentralized economy—especially as competition intensifies.

Challenges of the Fusaka Hard Fork

While Fusaka delivers major benefits, large-scale upgrades bring risks and challenges:

Hardware Requirements

Increasing the gas limit to 150 million means nodes must process more data, which could be hard for older hardware. However, PeerDAS and Verkle Trees reduce bandwidth and storage loads, partially offsetting new requirements. Most node operators can continue without major upgrades.

ETH Price Volatility

The ETH price may not immediately rise after the upgrade. Historically, major upgrades haven’t always led to price spikes, given macro factors like interest rates, global economics, and market sentiment. Investors should take a long-term perspective and avoid expecting short-term gains.

Coordination Complexity

With 12 EIPs and several BPO forks, Fusaka demands close collaboration among developers, validators, and node operators. Despite successful testnets and a $2 million bug bounty, careful deployment is essential to avoid issues.

Technical Risks

Every major upgrade carries the risk of bugs or unforeseen problems. Although testnet trials have been thorough, challenges may surface on mainnet at scale.

Successfully overcoming these challenges is key to Fusaka’s success and Ethereum’s long-term growth.

Fusaka Upgrade Roadmap and Next Steps

Fusaka’s deployment follows a strict roadmap for safety and stability:

Testnet Phase

The upgrade has passed key testnets:

• Holesky: First testnet for core feature validation
• Sepolia: Second testnet for stability checks in near-real conditions
• Hoodi: The "final rehearsal" before mainnet, simulating real-world scenarios

Mainnet Deployment

Slated for Q4, the mainnet will activate core EIPs like PeerDAS, Verkle Trees, and the 150 million gas limit. All Ethereum users will then experience Fusaka’s improvements.

BPO Forks

Once mainnet is stable, blob capacity will be adjusted via BPO forks:

• BPO1: Initial adjustment for cautious blob capacity increase
• BPO2 and beyond: Further increases based on real-world feedback and Layer 2 demand

Future Upgrades

Fusaka sets the stage for next upgrades like Glamsterdam, which will bring:

• Faster block times
• Stronger anti-censorship via proposer-builder separation
• Additional scaling and performance improvements

This roadmap reflects Ethereum’s careful yet determined approach to scaling while maintaining stability and security.

Conclusion: Fusaka’s Role in Ethereum’s Evolution

The Ethereum Fusaka upgrade, expected soon, marks a major step in making Ethereum faster, cheaper, and more efficient—especially for the rapidly expanding Layer 2 ecosystem.

With game-changing advances like PeerDAS, a 150 million gas limit, Verkle Trees, and a comprehensive set of EIPs, Fusaka confronts Ethereum’s toughest scalability and cost challenges, while upholding and strengthening its core value of decentralization.

Ecosystem-Wide Benefits

• Users benefit from low-fee, high-speed transactions
• Developers gain new tools and capabilities for innovative applications
• Validators can run nodes more easily with lower resource needs
• Enterprises enjoy enhanced security and lower operational expenses

Long-Term Vision

Despite possible price swings and technical hurdles, Fusaka remains the technological foundation of Ethereum’s leadership. The upgrade not only improves the present, but also prepares for future steps like Glamsterdam—further boosting scalability and efficiency.

Fusaka is more than a technical update—it’s Ethereum’s declaration to build a blockchain platform capable of serving billions globally, while preserving its core values of decentralization, security, and accessibility. This is why Fusaka is considered one of the most important upgrades in Ethereum’s history.

FAQ

What Is the Ethereum Fusaka Upgrade? How Is It Different from Previous Ethereum Versions?

Fusaka is an upgrade that expands Ethereum’s transaction capacity by raising the gas limit from 45 million to 150 million units per block. This significantly lowers transaction fees and boosts network performance.

Why Is the Ethereum Fusaka Upgrade Important? What Problems Does It Solve?

Fusaka dramatically reduces Layer 2 costs, standardizes blob fees, raises Layer 1 throughput to a 60M gas limit, and cuts validator workload by 85% via PeerDAS—enhancing network efficiency and decentralization.

How Does the Ethereum Fusaka Upgrade Affect Regular Users and Developers?

For users: Web2-like experience with logins that don’t require a seed phrase and native signing on mobile devices. For developers: Higher performance, lower node costs, and robust execution for complex contracts on Layer 1 and Layer 2.

How Will the Ethereum Fusaka Upgrade Improve Ethereum’s Performance and Security?

Fusaka increases the gas limit and rolls out advanced verification technologies like PeerDAS and Verkle Trees, boosting scalability while maintaining decentralization and security.

When Will the Ethereum Fusaka Upgrade Be Deployed? Do Users Need to Take Any Action?

The Ethereum Fusaka upgrade will be deployed on December 3, 2025. No special user action is required; nodes and clients will update automatically.