Ethereum’s highly anticipated hard fork Fusaka will activate with a major change to transaction gas limit cap.
The Ethereum Foundation said in a blog post on Tuesday, October 21, 2025 that Fusaka, the upcoming network upgrade, will feature an improvement proposal that sets the gas fee limit for each single transaction.
EIP-7825 will activate on the mainnet when Fusaka goes live, with rollout bringing a gas fee cap of 16.78 million gas per transaction.
According to EF, the limit is already live across the Holesky and Sepolia testnets.
Fusaka sees the changes activate on the Ethereum (ETH) mainnet.
While the gas fee cap limits the amount of gas each transaction can use, its application doesn’t impact overall block gas limit.
The cap also ensures that transaction blocks consist of several smaller and more predictable transactions – rather than one very large one.
As the change goes live on mainnet, one of the key things to note will be what developers and users relying on very large transactions should do.
Notably, the Ethereum Foundation advises that such users ensure their contracts and transaction builders align with the new cap.
The Fusaka upgrade went live on the Sepolia testnet earlier this month, after activation in the Holesky testnet.
Activation on the mainnet is the next step in Ethereum’s push to further boost network scalability and performance.
Fusaka is expected to launch on the mainnet on December 3, 2025. Currently, the Sepolia deployment allows for stress testing of features such as the ones outlined via EIP-7825.

