Ethereum’s Fusaka Hard Fork Introduces 16.78M Gas Cap Per Transaction with EIP-7825

Ethereum’s next major upgrade, the Fusaka hard fork, will introduce EIP-7825, setting a per-transaction gas limit cap of 2²⁴ (≈16.78 million gas). The change, already active on Holesky and Sepolia testnets, will go live on mainnet once Fusaka activates.

The new cap restricts how much gas a single transaction can consume, a move designed to reduce DoS risks and enable parallel execution in future Ethereum upgrades like EIP-7928 (Glamsterdam). Previously, one large transaction could use up an entire block’s ~45 million gas, limiting efficiency and preventing multi-threaded execution.

Under EIP-7825, blocks will now consist of multiple smaller, more predictable transactions, improving throughput and security without changing the overall block gas limit.

Minimal Impact for Most Users

For most Ethereum users, nothing will change, the vast majority of transactions already fall below 16 million gas. However, developers using batch transactions or heavy deployment scripts should test their contracts and refactor large operations into smaller chunks.

Developers are advised to:

• Test transactions on Sepolia or Holesky, which already enforce the new cap.
• Re-sign prebuilt transactions exceeding the 16.78M gas limit.
• Update tooling and gas estimation logic accordingly.

Step Toward Parallel Execution

The Fusaka update marks another milestone in Ethereum’s path to scalability. By enforcing a per-transaction gas limit, the network strengthens its foundation for parallel processing, paving the way for higher performance and more efficient block construction in future upgrades.

All major Ethereum clients, Geth, Erigon, Reth, Nethermind, and Besu, have already implemented the Fusaka changes in their latest releases.