The Ethereum Fusaka upgrade has completed the Sepolia test and will be launched on the Hoodi test network next. It is expected to land on the main network in early December.
The Ethereum Fusaka upgrade was officially launched on the Sepolia test network today (14th) and the test was successfully completed. The next step is to launch on the Hoodi testnet, which is the last testnet to undergo the upgrade. If all goes well with the Hoodi testnet, Fusaka is expected to hit the mainnet in early December.
(Preliminary summary: ETH is getting hard! Pectra, Fusaka, and Glamsterdam upgrade trio, core developers tell you where Ethereum will be in the future)
(Background supplement: One article to understand Ethereum Pectra upgrade: full analysis of various EIPs)
Contents of this article
Ethereum’s Fusaka upgrade will be officially launched on Sepolia today (14th) The test network was successfully launched and the test was successfully completed. The Daily Gwei founder @sassal0x posted on the data-width="500" data-dnt="true">
The Ethereum testnet, Sepolia, has been successfully upgraded to Fusaka!
Next up is the Hoodi testnet which is the final testnet being upgraded.
If all goes well with Hoodi, Fusaka should land on mainnet in early December.
— sassal.eth/acc 🦇🔊 (@sassal0x) October 14, 2025
What is the Fusaka upgrade? What are the features and improvements?
The Fusaka upgrade is another major upgrade of Ethereum after the Pectra upgrade in May 2025. It is designed to improve the scalability of the Ethereum network, reduce transaction fees, and optimize node operation efficiency. As part of the Ethereum scaling blueprint, Fusaka is focused on enhancing data availability and performance of the Layer 2 ecosystem.
Main features and improvements
PeerDAS: This is Fusaka's core technology, allowing validators to verify only data fragments without downloading complete "data blocks" (blobs). This improvement can reduce bandwidth and storage requirements by 90%, significantly reducing the cost of running a node, especially benefiting small validators or novice users.
Blob capacity expansion: Fusaka doubles data throughput by increasing the number of target blobs per block from 6 to 14 (maximum 21). This will significantly increase the transaction capacity of the L2 network.
Verkle Trees and EVM optimization: Verkle Trees are introduced to replace some Merkle Trees, providing smaller proof sizes and reducing data download requirements, especially suitable for mobile applications and low-resource devices. At the same time, EVM (Ethereum Virtual Machine) optimization will also simplify the user experience.
Gas fee reduction: Through bounded blob fees, the transaction fees of the L2 network will be further reduced, which is expected to alleviate the network congestion problem.
Timetable and Development Progress
The development progress of the Fusaka upgrade is progressing steadily. Following the successful launch on the Holesky testnet two weeks ago, the Sepolia testnet has been upgraded today. The developers plan to conduct the last test on the Hoodi test network on October 28. The Hoodi network is regarded as the most important indicator of Fusaka's performance because it is closer to the main network environment.
If the Hoodi test goes smoothly, Fusaka is expected to officially log on to the mainnet in early December 2025. It is worth mentioning that in order to ensure the safety of upgrades, the Ethereum Foundation also launched a four-week audit competition in September 2025, offering a bonus of up to US$2 million to discover potential vulnerabilities in the Fusaka code.
The analysis pointed out that with the advancement of Fusaka upgrade, Ethereum is accelerating to become a more efficient and user-friendly blockchain platform. This will not only solidify its position in the DeFi and NFT fields, but is also expected to attract more institutions and promote the widespread adoption of blockchain technology.
