Fusaka, the Ethereum hard fork: What can you expect?

Fusaka will be Ethereum’s major update in November. The focus is on improving security and performance behind the scenes rather than adding features to users.

Ethereum‘s next protocol upgrade, codenamed Fusaka, is entering its final testing and planning stages, with a mainnet activation tentatively scheduled for early November 2025.

Around six months after the Pectra Fusaka, the hard fork of Ethereum, continues its accelerated upgrade schedule and is focused on improving node performance and scalability. This will be especially beneficial to infrastructure providers, client developers, and blockchain service providers.

Fusaka, unlike Pectra which introduced user-facing features such as account abstraction, and increased validator limit, will not change the behavior of smart contracts. Fusaka bundles together 11 Ethereum Improvement Proposals, which refine protocol parameters and improve security.

Who is proposing and why?

EIP-7825 protects nodes by preventing them from receiving spam or other harmful messages. The block gas cap will be increased to 150,000,000, which allows more transactions per block. However, it comes at a cost, as the data storage and block distribution are affected.

Although EIP-7907 — which aimed to double the contract code size limit and introduce new gas metering rules — was considered, it was ultimately dropped to avoid testing delays. This may be addressed in a later fork.

The community has also spoken out. Nixo is a member of the Ethereum Protocol Supporter’s group has urged Team members must stick to strict deadlines so that Fusaka can be released in time for Devconnect. This is a crucial developer conference.

What’s inside the box

Here’s a bite‑sized look at some of the headline features Fusaka will bring:

• Gas limit increased. Raising the block gas limit to 150 million units so each block can include more transactions. The network will be faster and lower charges can be achieved.
• Security boosts (EIP‑7825). Nodes are made more resilient and less susceptible to network disruptions by new checks that guard against specific attack patterns.
• Adjustments to code size and metering. Although EIP‑7907— which would double the code size limit and add new gas charges — was pulled to speed testing, future forks may possibly revisit it.

In general, the changes made won’t have any noticeable effect on how smart contracts function. These changes will allow the network to process more traffic faster and safer.

What brought us here?

Ethereum follows a roughly six‑month upgrade cycle. Pectra was the last major fork to go live, and it brought features such as account abstraction, higher stake limits, etc. Shortly after Pectra’s release, discussions began about the next step, and Fusaka rose to the top of the list by mid‑2025.

Ethereum’s AllCoreDevs, a regular meeting of the protocol teams, discussed behind closed doors which EIPs should be bundled. On Aug. 1, the final set of EIPs for Fusaka will be confirmed and frozen, giving client teams a month or two to bake in the changes. Ethereum’s Fusaka upgrade path looks as follows:

1. Launch of Devnet The first developer‑only network went live in mid‑July 2025, letting researchers and node‑software teams test new code in a controlled setting.
2. Public Test Nets Two public testnets are scheduled for late September and October 2025, opening the door to broader community testing and bug‑hunting.
3. Mainnet hard fork. Fusaka will be activated on Ethereum’s mainnet, barring any setbacks major, in November. This is ideally just before Devconnect in Buenos Aires (17-22 Nov.).

If everything goes smoothly, developers will tally up testnet results in November and roll out the upgrade at a pre‑announced block height, ensuring all nodes upgrade together.

Users will stay with blockchains which are cheap, fast and secure in the long term. Fusaka doesn’t represent a radical overhaul of Ethereum, but it is an important step in helping Ethereum compete with layer-2s and faster chains. The network could be made more friendly to DeFi applications, games and other uses by boosting capacity and improving defenses.