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Tanay Ved, Coinmetrics analyst; Translation: @bitchainvisionxz
1, abstract
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Improved scalability: Fusaka improves Ethereum’s scalability by providing higher blob capacity and a more efficient data availability system through PeerDAS (Peer-to-Peer Data Availability Sampling).
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L1 throughput increased: Up to 60 million Gas limits and execution layer optimizations significantly improve L1 throughput.
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Cost and user experience optimization: Fee mechanism improvements and user experience upgrades lay the foundation for a more unified and cost-effective L1-L2 ecosystem.
2,FusakaUpgrade overview
Ethereum plans to conduct its next upgrade at 21:49 UTC on December 3, 2025 (slot 13,164,544). This hard fork is called “Fusaka”.Fusaka combines the execution layer upgrade “Osaka” and the consensus layer upgrade “Fulu”, following the naming convention of previous forks.
Following the Pectra upgrade in May, Fusaka marks an important step on Ethereum’s scaling roadmap, enhancing layer-1 performance, expanding blob capacity, improving the cost-effectiveness of rollups, and delivering user experience upgrades.It also introduces a “Blob parameter only” forking mechanism to safely increase blob capacity as Rollup demand grows.Earlier this year, the Ethereum Foundation outlined its “protocol” strategy, which is centered around three long-term goals: scaling L1, scaling blobs, and improving user experience.Fusaka is the first upgrade to fully align with this unified vision, marking a turning point in how Ethereum plans and improves scalability and accessibility in the future.
This article will outline the key changes in the Fusaka upgrade and its expected impact on the Ethereum mainnet, second-layer rollup, transaction costs, and user experience.
3,BlobExpand
Last year’s Dencun upgrade introduced “Blobs” – a cost-effective solution for Rollup to store transaction data on the Ethereum mainnet.Since then, thanks to the widespread adoption of Rollups such as Base, Arbitrum, and Lighter, Blob usage has often been close to saturation (currently close to the target value of 6 Blobs per block), resulting in the risk of an exponential surge in Rollup fees.The growth in data availability requirements has made Blob space a key bottleneck in Ethereum’s expansion path, and the Fusaka upgrade aims to break through this limitation.
(1)PeerDAS: Peer-to-peer data availability sampling
PeerDAS (EIP-7594) is the most significant improvement in the Fusaka upgrade and directly fits the goal of expanding L1 and Blob capacity.This technology introduces a more efficient data availability verification mechanism for Ethereum nodes: nodes do not need to download complete Blob data, but implement verification by sampling fragmented data, reducing the load on L1 consensus nodes while ensuring the same security.
Expected impact:
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Nodes only need to store about 1/8 of the data volume of each Blob, which can significantly increase Blob throughput without increasing hardware requirements.
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Ethereum can safely increase Blob throughput – this is the core driving force for Rollup expansion.
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Lower data availability costs will reduce L2 transaction fees and improve batch submission reliability.
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Laying the foundation for the full version of Danksharding and higher transaction throughput of the entire ecosystem.For example, Base stated in a blog post that Fusaka’s upgraded L2 expansion improvements can enable it to “double its chain throughput within 2 months.”
(2) BPO fork
With PeerDS reducing the bandwidth and storage required for nodes to verify blob data, Ethereum can now safely increase blob capacity.The Fusaka upgrade introduces a “Blob Parameter Only” (BPO) adjustment mechanism designed to gradually increase the number of blobs per block.This allows Ethereum to adjust blob parameters without waiting for a complete hard fork, providing the protocol with a more flexible and responsive expansion tool.
Upcoming BPO fork plans:
Expected impact:
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Improve data availability bandwidth: Gradually increase the rollup capacity of each block from 6 Blobs to 128 Blobs, and reduce L2 transaction fees.
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Achieve elastic expansion: Blob parameters can be dynamically adjusted according to demand growth.
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Build a progressive evolution path: In line with Ethereum’s roadmap to reduce Rollup execution costs and achieve scalable data availability.
(3)BlobBasic cost adjustment
As blob capacity expands, Ethereum’s blob fee market will play a greater role in coordinating rollup demand.Currently, Rollup spends very little on blobs.Since demand is relatively insensitive to price and fees cannot be adjusted smoothly with usage, Blob fees are often maintained at a minimum of 1 wei.This results in the fee mechanism being in a “price inelastic” range, limiting its ability to respond to changes in usage.
The Fusaka upgrade sets a lower limit on costs by linking the Blob base fee with the L1 base fee.This action prevents Blob prices from plummeting to zero and ensures that the fee adjustment mechanism continues to be effective during the Blob capacity expansion process.The specific impacts are as follows:
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More stable blob pricing: Avoid the lowest price deadlock in the fee market.
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Predictable Rollup Economic Model: Ensure that Rollup pays reasonable baseline fees for data availability to avoid sudden fee fluctuations.
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Minimal impact on user costs: Even with the new lower limit, L2 data cost is still less than 1 cent, and the impact on user experience is negligible.
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Sustainable long-term economic ecology: Compensate nodes that handle growing Blob traffic. Although the current Blob fee has a limited contribution to ETH burning, it has considerable potential in the future as capacity expands.
4,L1Expansion
Fusaka upgrade also attaches great importance to L1 expansion.Through the EIP-7935 proposal, it increases the default Gas limit of the protocol to 60 million, significantly enhancing the execution capabilities of the Ethereum layer one network.This improvement directly increases the number of transactions that can be accommodated in a single block, resulting in higher throughput, lower network congestion, and reduced gas fees.
Expected impact:
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Improve throughput: Each block can carry more calculations and enhance the overall processing capability of L1.
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Support complex applications: A higher Gas limit provides room for complex contract execution.
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Alleviating high load congestion: Additional capacity buffering reduces network congestion during traffic peaks.
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Maintain the advantage of low rates: The expanded network capability supports the current low gas fee environment (<0.4 gwei).
In addition to increasing the gas limit, Fusaka has also introduced a number of optimization measures aimed at improving L1 execution efficiency and paving the way for future expansion.Among them, the setting of the gas usage limit for a single transaction prevents any transaction from monopolizing the entire block and lays the foundation for parallel execution; the update of the ModExp precompiled contract recalibrates the gas cost and sets clearer boundaries for computing operations, ensuring that resource consumption remains predictable as throughput increases; the network layer is also streamlined by removing redundant fields before merging, making Ethereum node synchronization faster and lighter load.
5, optimize user experience
The Fusaka upgrade also introduces a number of updates that improve usability for developers and end users.EIP-7951 adds native support for secp256r1 elliptic curves, the signature standard used by Apple Secure Enclave, Android Keystore, and most consumer hardware.This will allow wallets and applications to directly integrate familiar authentication processes such as Face ID, Touch ID, WebAuthn, etc., while lowering the threshold for new users while providing stronger security for retail and institutional users.
These upgrades help modernize the Ethereum development interface and user interaction experience, making it easier to build applications that are secure and suitable for mainstream users.
6, conclusion
The most direct impact of the Fusaka upgrade will be reflected in the reduction of Rollup costs, the improvement of Blob throughput, and the significant expansion of L1 execution capabilities.In the long term, the expansion of Blob space, cost optimization and continuous improvement of L1 performance will jointly shape the economic model of L2 settlement, affect the deflation dynamics of ETH, and continuously enhance the synergy of the entire Ethereum ecosystem.
While long-term value ultimately depends on the accumulation of demand and adoption, Fusaka lays a clearer, scalable foundation for Ethereum’s next phase of growth—on which L1 and L2 will work more seamlessly, and the network will better support a larger scale of users, assets, and on-chain activities.
