Ethereum’s Fusaka Upgrade Deployed on Sepolia Testnet

Ethereum’s Fusaka testnet upgrade introduced major scaling improvements and PeerDAS technology, paving the way for a more efficient mainnet rollout.

(Photo of Viktor Forgacs on Unsplash)

Posted October 15, 2025 at 10:17 am ET.

Ethereum’s Fusaka upgrade was successfully activated on the Sepolia testnet on Tuesday in preparation for its mainnet launch scheduled for early December.

The Fusaka upgrade is a significant milestone in Ethereum’s scaling and performance roadmap, representing the second stage in a three-step process following trials on the Holesky testnet earlier in October.

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Its features include raising the block gas limit to 60 million, which will allow more transactions and complex smart contracts to be processed per block.

The centerpiece of Fusaka is PeerDAS (Peer Data Availability Sampling, EIP-7594), a technology that allows validators to verify transaction data by sampling small portions from multiple peers instead of downloading and storing it in full.