Ethereum’s long-awaited hard fork Fusaka is activated with significant changes to the upper transaction gas limit.
summary
- The Ethereum Foundation has announced that the deployment of Fusaka on mainnet will enable per-transaction gas limits.
- Gas price cap starts with EIP-7825
- Ethereum’s fusaka upgrade went live on the Holesky and Sepoila testnets in October of this year.
The Ethereum Foundation said in a blog post on Tuesday, October 21, 2025, that the upcoming network upgrade to Fusaka will include an improvement proposal to set gas fee limits on a per-single transaction basis.
Once Fusaka goes live, EIP-7825 will be active on mainnet, and the rollout will bring the gas price cap per transaction to 16.78 million gas.
According to EF, this restriction is already in place across the Holesky and Sepolia testnets.
Fusaka sees the changes becoming active on the Ethereum (ETH) mainnet.
“Previously, a single transaction could consume the entire block gas limit (approximately 45 million gas), creating a potential DoS risk and preventing parallel execution. EIP-7825 established a hard limit of 2²4 gas per transaction to improve block packing efficiency and pave the way for improved parallelism in future execution environments,” EF writes.
You may also like: Ethereum researcher Danclad Feist joins Stripe-backed Tempo project
What does that mean for users?
A gas fee cap limits the amount of gas that can be used in each transaction, but its application does not affect the overall block gas limit.
This limit also ensures that a transaction block is made up of smaller, more predictable transactions rather than one very large transaction.
As this change makes its way to mainnet, one of the key things to keep an eye on will be what developers and users who rely on very large transactions should do.
In particular, the Ethereum Foundation advises such users to ensure that their contracts and transaction builders align with the new cap.
“For most users, nothing changes. The majority of transactions are already well below 16 million gas,” said Ethereum Foundation researcher Toni Wahlstetter. “However, certain contracts and deployment scripts, especially those that perform batch operations, may exceed this limit. Once Fusaka is active, such transactions will be invalidated.”
When will Fusaka be upgraded?
The Fusaka upgrade went live on the Sepolia testnet earlier this month after being activated on the Holesky testnet.
Activation on mainnet is the next step in Ethereum's efforts to further improve the network's scalability and performance.
Fusaka is scheduled to launch on mainnet on December 3, 2025. Sepolia deployments currently allow stress testing of features such as those outlined in EIP-7825.
You may also like: Polygon and Sonic Labs co-founder criticizes Ethereum Foundation for ignoring Layer 2
