Author: imToken
On June 20, at the 214th Ethereum Execution Layer Core Developer Meeting (ACDE), core developers agreed to keep the final scope of the Fusaka upgrade largely unchanged, only adding an additional EIP (EIP 7939), which covers 12 EIPs. This also marks the official transition of Fusaka from the 'planning' stage to the 'substantive implementation' stage.
As the largest hard fork bundled upgrade since the Merge, the market generally expects that if Fusaka can be launched as planned by the end of 2025, it will bring another round of order-of-magnitude improvement to the L2 data space, potentially leading to further reductions in Layer 2 transaction fees within the next 1-2 years, thus consolidating Ethereum's position in front of its competitors.
The continuous expansion logic of Ethereum's roadmap
It is well known that Ethereum's scalability issue was once a core bottleneck, resulting in high on-chain costs and difficulty in popularizing DApps.
According to data publicly shared by Vitalik in April this year, Ethereum's L1 throughput is 15 transactions per second, and the gas limit has recently increased to 36 million, approximately a sixfold increase over the past 10 years.
At the same time, more significant changes have occurred in Ethereum Layer 2, where the current Layer 2 throughput has reached approximately 250 TPS, achieving significant progress in scalability. This capability is not just on paper; many users have also clearly felt the reduction in costs and acceleration of on-chain operations:
In the past year, whether it was Arbitrum, Optimism, or Base, Layer 2 transfer fees generally fell to the range of $0.01 or even lower, achieving a drop of one or more orders of magnitude compared to before. The daily gas costs on the Ethereum mainnet have also become significantly friendlier (of course, the market conditions and on-chain activity levels may still play a role).
This shift is not coincidental, but rather a result of Ethereum adhering strictly to its roadmap and continuously iterating and advancing it. We can briefly review the key upgrades of the Ethereum network in recent years:
In 2022, Ethereum successfully transitioned to a PoS mechanism through the Merge upgrade,
greatly reducing energy consumption and freeing up execution layer bandwidth for subsequent upgrades;
In 2024, the Dencun upgrade was successfully activated, introducing the Blob data mechanism,
Providing low-cost, temporary storage space for Layer 2, dramatically reducing Rollup costs and opening up scalability;
The recent Pectra upgrade successfully went online on May 7, significantly optimizing the validator operation process and enhancing the flexibility of participation in the PoS system;
The next step, the Fusaka upgrade, is a key step in continuing the aforementioned progress.
According to the latest statement from Tomasz Kajetan Stańczak, Joint Executive Director of the Ethereum Foundation, Fusaka is expected to launch on the mainnet in the third or fourth quarter of 2025 (time to be finalized) and plans to implement several core EIPs, including PeerDAS data availability sampling, further advancing Ethereum from performance bottlenecks to mainstream applicability.
It can be said that from The Merge → Dencun → Pectra → Fusaka, Ethereum is methodically advancing towards its long-term blueprint, which is to build a global network that combines security, scalability, decentralization, and sustainability.
Overview of the Fusaka upgrade
From the 12 core EIPs included in this upgrade, they cover multiple technical dimensions including data availability, lightweight nodes, EVM optimization, and the collaborative mechanism between the execution layer and the data layer.
Among them, the most notable proposal in this Fusaka upgrade is EIP‑7594 (PeerDAS), which introduces a mechanism for 'Data Availability Sampling (DAS)', allowing validators in the network to complete validation by downloading only a portion of the Blob data, without needing to store all the data in full.
This greatly reduces the network burden, increases validation efficiency, and paves the way for large-scale transaction processing capabilities on Layer 2, with the concept of 'Blob' tracing back to the EIP-4844 introduced in the Dencun upgrade in 2024.
As the most important milestone for Ethereum in 2024, the Dencun upgrade's EIP-4844 enabled transactions carrying Blobs for the first time, allowing Layer 2s to opt out of using the traditional calldata storage mechanism, significantly improving the gas costs for transactions and transfers on Layer 2.
So what are transactions carrying Blobs? In short, it involves embedding a large amount of transaction data into a Blob, thus significantly reducing the storage and processing burden on the Ethereum mainnet, not counted towards Ethereum's mainnet state, directly addressing the L1 cost issues related to data availability, ensuring that Layer 2 platforms can provide cheaper and faster transactions without compromising the security and decentralization based on Ethereum.
The Blob expansion here is also based on Pectra — the Pectra upgrade in May increased Blob capacity from 3 to 6. Notably, Vitalik has publicly stated that ideally, Fusaka will expand Blob capacity to 72 per block (initially growing to 12-24), and if DAS is fully realized in the future, the theoretical maximum capacity could reach 512 Blobs per block.
Once implemented, Layer 2's processing capacity (TPS) is expected to leap to tens of thousands, significantly enhancing the usability and cost structure of high-frequency interaction scenarios such as on-chain DApps, DeFi, social networks, and games. This is also one of the core directions in Vitalik's previously proposed (L2 security and finalization roadmap).
At the same time, the Fusaka upgrade plans to achieve lightweight state and node structure by introducing Verkle trees, which not only significantly compress the size of state proofs, making light clients and stateless validation possible, but also help promote Ethereum's decentralization and mobile adoption.
In addition, Fusaka also focuses on the flexibility and performance bottlenecks of the virtual machine layer (EVM), including the following proposals:
EVM and contract optimization rely on EIP‑7939 (CLZ opcode): efficiently implementing bit operations to accelerate encryption computations;
EIP‑7951 (secp256r1 replacement support): enhancing compatibility with Web2 and enterprise architectures;
EIP‑7907: expanding the contract size limit, supporting the deployment of more complex logic, and enhancing developer flexibility;
To ensure that expansion does not affect network stability, Fusaka also introduces EIP‑7934 to set block size limits, ensuring that blocks do not become too heavy due to Blob expansion, and adjusts the costs for using Blobs through EIP-7892 / EIP-7918 to prevent resource abuse and dynamically match supply and demand fluctuations.
Is Ethereum's expansion and experience a turning point?
Overall, we will find that Fusaka is not just a technical upgrade, but is also expected to lay the foundation for the bridge from 'scalability to usability' on multiple key levels.
For example, for Rollup developers, it means lower data writing costs and more flexible interaction space; for wallet and infrastructure providers, it means supporting more complex interactions and heavier load node environments; for end users, it means lower experience costs and faster response for on-chain operations; for enterprises and compliant users, EVM expansion and state proof simplification will also make on-chain interactions easier to integrate into regulatory systems and large-scale deployments.
However, caution is still warranted. As of the time of writing, Fusaka is still undergoing testing on multiple Devnets, and the final launch date may still change. In an optimistic scenario, Fusaka is expected to complete its mainnet deployment by the end of 2025, which may become another important milestone in Ethereum's history after the Merge.
Overall, Fusaka is not just limited to enhancing on-chain scalability, but also represents a key step for Ethereum's transition to mainstream commercial applications and ordinary users, expected to provide a technical foundation for the next stage of the Rollup ecosystem, enterprise-level DApps, and on-chain user experience.
The true turning point for Ethereum towards large-scale mainstream applications may be approaching.
