Ethereum’s Fusaka Upgrade is Set to Land, Promising Cheaper Transactions and a Faster Future
Ethereum developers are putting the final touches on the next massive upgrade for the world’s leading smart contract platform, a major network overhaul known as **Fusaka**. Scheduled to go live on December 3, 2025, this hard fork is the second major update of the year, following the Pectra upgrade in May, and it’s shaping up to be one of the most critical steps yet in Ethereum’s quest for mass scalability.
The name “Fusaka” is a clever portmanteau, combining the previous project titles for the execution layer (Osaka) and the consensus layer (Fulu). It signifies a highly coordinated change across both core parts of the network, and the goal is straightforward: make Ethereum significantly cheaper and faster for the millions of users currently relying on Layer 2 (L2) solutions like Arbitrum and zkSync.
The Scaling Game-Changer: PeerDAS
If there’s one feature you need to know about in the Fusaka upgrade, it’s **Peer Data Availability Sampling**, or PeerDAS. This is the real game-changer. Following the Dencun upgrade’s introduction of temporary data “blobs” for L2 transactions, all nodes still had to download and store this huge amount of data. This created bottlenecks and increased the hardware requirements for people running a full node.
PeerDAS completely changes that dynamic. Instead of downloading every single piece of data, network validators will now be able to verify data by randomly sampling small, manageable portions of a blob from other nodes. This innovative process uses advanced cryptography to ensure data is available without forcing everyone to store the entire dataset. For the average user, this means the network can safely handle a much higher volume of transactions without burdening home node operators, preserving the network’s decentralization.
Lower L2 Fees and Gradual Capacity Boosts
The impact of PeerDAS on Layer 2 networks cannot be overstated. By dramatically increasing the efficiency of data handling, analysts expect L2 transaction fees to fall by another 60 to 90 percent in the months following the upgrade. This is a crucial step towards making decentralized applications truly accessible to a global audience.
Furthermore, Fusaka introduces a new mechanism called **Blob Parameter Only (BPO) Forks**. After the initial activation on December 3, the BPO forks allow the number of data blobs per block to be gradually increased in a staged, safe rollout. The first BPO is planned for later in December, with a second in early January 2026, effectively scaling the network’s data capacity without needing another major hard fork event. This modular approach is key to achieving Ethereum’s long-term goal of processing over 100,000 transactions per second via Layer 2 solutions.
Beyond the core scaling features, Fusaka also includes important quality-of-life updates. Developers are incorporating support for the P-256 cryptographic signature scheme, which could enable user-friendly features like signing transactions directly with an iPhone’s FaceID or TouchID. There is also a substantial increase to the Layer-1 gas limit, which provides more room for base-layer transactions.
By building on the foundations laid by Pectra earlier in the year, the Fusaka upgrade represents a powerful stride into the next chapter of Ethereum’s evolution, delivering on the promise of a platform that is faster, cheaper, and more robust for everyone.