Fusaka Testnet Announcement | Ether Leeum Foundation Blog
Fusaka follows this year PECTRA upgradePEERDAS and major improvements that improve BLOB throughput, L1 performance and user experience indicate major progress in Ethereum’s scaling roadmap.
This post starts with HOLESKY in Slot and announces the testnet activation schedule of the first three test nets. 5,283,840 (October 1, 2025, 08:48:00 UTC). reference Activation table For the entire Sepolia and Hoodi timeline. FUSAKA also introduces the BPO (Blob Parameter Only) fork to safely scaly the blobs through the Pierdas activation. These are the minimum configuration upgrades that adjust the BLOB TARGET/MAX and fees update fractions.
Fusaka testnet client release is listed Below. If all three test nets are successfully upgraded, the main net activation slot is selected.
Fast outline
Fusaka’s headline EIP enables significant blobed through processing scale scaling with peerdas. The upgrade also includes execution and optimization of consensus layers to expand L1 performance and improve user experience. This post briefly explains the main improvements. See for more comprehensive outline Ethereum.org upgrade guide.
Scale Blow V: Pierdas
EIP-7594 Introducing PEERDAS, a new networking protocol that allows the node to check the use of blobs data through sampling without downloading a complete blove. This is the key stage of expanding the amount of blobs while maintaining Ether Leeum’s security and decentralization.
since Dencun upgradeLayer 2 usage grows in fact, and often reaches nine stains per block limit. PEERDAS allows Ethereum to increase this limit without any security. Use Erassure Coding to encrypt that the entire data can be used throughout the network while allowing nodes to sample some of the blob data. This creates a way toward higher BLOB goals summarized in Ether Leeum. Scaling Roadmap.
This sampling approach does not increase the bandwidth requirements of individual nodes, but also provides direct profits to layer 2 rollups by supporting higher blobstrate. The BLOB capacity exceeds the current limit, and the L2 transaction fee can be further reduced while maintaining the security guarantee of Ethereum L1’s data availability.
After the PEERDAS is enabled, Ethereum uses the BLOB-Parameter-only (BPO) fork to safely lamp the BlOB throughput. Fusaka includes two planned BPO parameters adjustments for HOLESKY from October 7, 2025, and has a similar schedule for other test nets. This BPO increases the blot goal per block from 6 & 9 to 10 & 15, and 14 & 21 in BPO2, respectively.
Scale L1
MODEXP Optimization
EIP-7883 and EIP-7823 Cooperate together to optimize MODEXP Precompile. EIP-7883 increases gas costs to minimize gas costs and to more accurately reflect computational complexity, including general cost calculations. EIP-7823 sets the upper limit of MODEXP work. These changes together, the resource -intensive encryption work allows the price to be appropriately priced and the potential future block gas limits can be increased.
Transaction gas limited cap
EIP-7825 Protocol -level transaction gas limit caps implement 16,777,216 gas gas to prevent individual transactions from consuming excessive block gas and protecting them from DOS attacks. This lays the foundation for parallel transaction processing in EVM.
Network protocol optimization
EIP-7642 Introducing ETH/69 to remove the Bloom from the free margar field and networking protocol. This theorem simplifies the codebase by reducing the requirements of synchronous bandwidth, adding explicit records that the node can advertise, and removing the legacy components that are no longer necessary after the data.
Increased gas limitations
EIP-7935 The core developer raises the basic gas limit of Ether Leeum to 60mm, reflecting the gas restrictions that Etherum L1 can expand safely. This increase has been thoroughly tested in other client combinations to enable more L1 execution capacity and to ensure network stability and security.
In addition to this performance improvement, Fusaka improves user and developer experience with multiple target upgrades.
UX improvement
Secp256R1 is incomplete
EIP-7951 The new leading agreement adds basic support for ellipse of ellipse of SECP256R1. Through this, it is integrated directly with the latest security hardware such as Apple Secure Enclave, Android Keystore and FIDO2/WebauthN.
Calculate the main 0 Zeros opcode
EIP-7939 Introducing CLZ (Count Leading Zeros) OPCode to provide a basic and gas efficient way to perform basic bit calculation tasks. This addition is to reduce ZK proof costs by supporting mathematics operations, compressed algorithms and signature systems after quantum.
Anger
The full change list of changes introduced in fusaka EIP-7607. The core EIP includes:
Additional Support EIP:
All specifications for execution and consensus layer changes are available in the following release.
Fusaka also introduces changes in the engine API used for communication between the consensus and the execution layer nodes. These are Osaka Run -APIS Repository File.
Anger security
Security Research Institute can participate next time Fusaka Thanksgiving Competition It helps to identify potential problems before the Mainnet deployment.
Fusaka activation
The Fusaka Network upgrade is activated in Holesky, Sepolia and Hoodi Testnet:
| network | slot | UTC time | Unix Time Stamp |
|---|---|---|---|
| Holzuki | 5,283,840 | 2025-10-01 08:48:00 | 1759308480 |
| Sepolia | 8,724,480 | 2025-10-14 07:36:00 | 1760427360 |
| hood | 1,622,016 | 2025-10-28 18:53:12 | 1761677592 |
As previously announcedFusaka will be the last network upgrade distributed to HOLESKY. It is terminated immediately after the upgrade is deployed.
BLOB parameter only (BPO) fork schedule
Following the activation of the main Husaka, the network implements only a blove parameter that gradually increases the amount of blobs. BPO1 increases the Blove goal per block and increases up to 10 and 15. BPO2 increases the target to 14 and up to 21.
HOLESKY BPO Schedule
| BPO fork | times | Date and time (UTC) | Unix Time Stamp |
|---|---|---|---|
| BPO1 | 166,400 | 2025-10-07 01:20:00 | 1759800000 |
| BPO2 | 167,936 | 2025-10-13 21:10:24 | 1760389824 |
BPO SEPOLI Schedule
| BPO fork | times | Date and time (UTC) | Unix Time Stamp |
|---|---|---|---|
| BPO1 | 274,176 | 2025-10-21 03:26:24 | 1761017184 |
| BPO2 | 275,712 | 2025-10-27 23:16:48 | 1761607008 |
Hoodi BPO schedule
| BPO fork | times | Date and time (UTC) | Unix Time Stamp |
|---|---|---|---|
| BPO1 | 52,480 | 2025-11-05 18:02:00 | 1762365720 |
| BPO2 | 54,016 | 2025-11-12 13:52:24 | 1762955544 |
Client release
The following client release is suitable for the fusaka upgrade. All three tests. The additional version activates support in Mainnet. If these are released, another presentation will be made in this blog.
Consensus Layer HOLESKY, SEPOLIA & HOODI Release
When running an validation tester, you need to update both consensus layer Beacon Node and Validator clients.
memo: Lodestar users must always use the latest RC Listed in the version Release page.
Execution layer HOLESKY, SEPOLIA & HOODI Release
FAQ
How does the Ether Leeum network upgrade work?
The Ether Leeum Network Upgrade requires a clear opt in from the node operator of the network. Customer developers are agreed to contain EIPs in the upgrade, but they are not ultimate determinants of adoption.
In the case of Go LIVE, the validation tester and the non -staying node must support the change of protocols that are introduced by manually updating software.
If you use the latest version of Etherrium Client (listed above), the upgraded peer is broken in the fork block, making it a fork for the network. In this scenario, each sub -set of network nodes is connected to those who share upgraded (UN) upgraded state.
Most Etherum Upgrades are not consecutive and rarely lead to forks, but the options to adjust whether the node operator will support upgrade is the main feature of Etherum Governance.
The more thorough outline of Ether Lee’s governance process Tim Beiko’s story.
Is there anything I have to do as an Ether Leeum Mainnet user or ETH holder?
In short, no.
This announcement is associated with Ether Leeum test. There will be additional announcements on the activation of fusaka in Ethereum Mainnet, but until then, Ethereum Mainnet users and ETH holders do not have to take action.
What should I do as a test net node operator without a stage?
To be compatible with the upgrade of this test net, update the node’s execution and consensus layer client to the version listed in the table above.
What should I do as a testnet staker?
To be compatible with the upgrade of this test net, update the node’s execution and consensus layer client to the version listed in the table above. Make sure that both beacon nodes and validation clients have been updated.
What should I do as a non -testnet node operator or steak?
There is nothing now. There will be additional announcements on the activation of fusaka in Mainnet.
What should I do as an application or tooling developer?
Review the EIP included in fusaka to see how it affects the project. PEERDAS, SECP256R1 support and the introduction of the new CLZ opcode offers interesting opportunities for function and performance optimization.
Why “face”?
Upgrading to the executive layer follows the DEVCON City name, and the consensus layer uses the name of the star. “Fusaka” is a combination of OSAKA, the position of Fulu and Devcon V, a star in Cassiopeia’s constellation.
