Ethereum Fusaka Is Live: What the Hard Fork Means for Fees, Rollups, and Users

Ethereum’s highly anticipated Fusaka upgrade went live on December 3, 2025, becoming the network’s second major hard fork of the year and one of its most ambitious scaling steps to date. Fusaka introduces Peer Data Availability Sampling, a system that allows validators to check data through lightweight sampling rather than downloading entire data blobs. Alongside an expanded block gas limit and several performance-driven improvements, the upgrade is designed to push Ethereum toward faster throughput, lower transaction costs and greater efficiency for the Layer 2 rollups that depend on it.

For everyday users and crypto investors, Fusaka signals a turning point in how Ethereum manages traffic and network demand. The upgrade unlocks significantly more data capacity for rollups, helps stabilize fees at low levels and adds user-focused improvements such as support for biometric-friendly passkeys. While the technical work takes place behind the scenes, the visible result across the ecosystem is expected to be simple: more breathing room, cheaper activity and a smoother experience from wallets to decentralized applications.

Read more: Ethereum Fusaka Upgrade: What You Need to Know

What Is Fusaka?

Fusaka is Ethereum’s seventeenth major network upgrade and is part of the platform’s steady, twice-a-year improvement cycle. It follows the naming tradition of combining the execution layer and consensus layer themes. The “Fulu” star represents the consensus component, while “Osaka,” the host city of Devcon 2025, represents the execution side. Together they form the name Fusaka, marking a symbolic fusion of Ethereum’s technical roadmap and community milestones.

The upgrade arrives after several years of rapid transformation on Ethereum. The Merge in 2022 shifted the network to proof of stake. Shanghai in 2023 introduced withdrawals for staked ETH. Dencun in 2024 delivered data blobs, which cut rollup fees by roughly ninety percent. Pectra in mid-2025 expanded blob capacity and refined validator operations. Fusaka continues this progression by introducing PeerDAS and raising network throughput, pushing Ethereum further along its scaling vision and preparing the ground for future steps toward full Danksharding.

PeerDAS: A Data-Scaling Breakthrough

At the heart of Fusaka is Peer Data Availability Sampling, better known as PeerDAS. This system fundamentally changes how Ethereum nodes verify the data posted by Layer 2 rollups. Instead of downloading entire blobs of data, validators now check only small, random samples. When thousands of validators each sample different parts, the network gains high confidence that the full data set is available and valid. This method significantly reduces the bandwidth and storage burden on validators and makes it much easier for home stakers to keep pace with the chain.

The impact of PeerDAS is substantial. By shifting from full data downloads to sampling, Ethereum reduces validator bandwidth requirements by close to eighty five percent. This opens the door to much larger data capacity on every block, which directly benefits rollups that rely on Ethereum for data publishing. Early testing shows that PeerDAS can support several times more blob space than before, potentially multiplying Ethereum’s Layer 2 transaction throughput and unlocking new levels of scalability. With PeerDAS now live, Ethereum takes a meaningful step toward the high-throughput future envisioned in its roadmap.

Bigger Blocks and Smarter Upgrades

Fusaka does more than introduce PeerDAS. It also expands Ethereum’s raw capacity on the base layer by raising the default block gas limit from around thirty six million to sixty million gas. This increase allows significantly more activity to fit inside each block, whether it is regular transactions or more complex smart contract operations. At the same time, the upgrade includes safety features to prevent any single transaction from overwhelming the network. A per-transaction gas cap ensures that no computation-heavy transaction can monopolize block space, maintaining stable performance even under higher throughput.

Alongside these changes, Fusaka introduces new cryptographic and virtual machine improvements that enhance Ethereum’s usability and efficiency. A notable addition is support for secp256r1 signatures, which brings device-native authentication to Ethereum. This allows wallets to integrate biometric methods such as fingerprint and facial recognition for signing transactions, creating a more intuitive login experience without relying solely on seed phrases. Fusaka also adds new EVM instructions and optimizations that make smart contracts cheaper and easier to operate. These enhancements strengthen Ethereum’s foundations while preparing the network for future scaling stages.

Lower Fees

One of the most noticeable outcomes of the Fusaka upgrade is its impact on transaction costs across the Ethereum ecosystem. By expanding the amount of data the network can handle and increasing the space available for rollup batches, Fusaka helps relieve congestion at its source. Analysts estimate that Layer 2 data fees could fall by roughly forty to sixty percent as a direct result of the added blob capacity. This reduction is expected to keep rollup transactions consistently inexpensive, even during periods of heightened on-chain activity.

Ethereum’s base-layer gas fees should also benefit from the upgrade. With more room inside every block and more efficient data handling through PeerDAS, the network is less likely to experience sharp fee spikes when demand rises. To maintain healthy economics, Fusaka introduces a minimum blob fee that sets a baseline cost for rollup data, ensuring fees do not drop to zero while still remaining extremely low for users. For both Ethereum mainnet and Layer 2 networks, the result is a more predictable and affordable environment that supports everyday usage and encourages broader adoption.

Rollups Supercharged

Layer 2 rollups stand to gain the most from the Fusaka upgrade, as the improvements directly expand the amount of data Ethereum can make available each block. With significantly more blob space and the efficiency of PeerDAS, rollups can publish larger and more frequent batches of transactions, allowing them to handle many times their current throughput. Early estimates suggest that rollups could see more than triple the data capacity they previously had, unlocking the potential for ecosystem-wide transaction speeds that reach into the tens of thousands per second.

This new capacity gives rollups a wider runway to grow without facing the bottlenecks that used to push fees higher during busy periods. Arbitrum, Optimism, Base and other major Layer 2 networks can now compress more activity into each posting, making fees cheaper and performance more consistent for their users. Fusaka also prepares Ethereum for future “blob-only” expansions that can further increase throughput without requiring another full-scale hard fork. As a result, the rollup-centric model at the core of Ethereum’s scaling strategy becomes stronger, more flexible and better positioned to support mainstream applications.

Better Experience for Users

For everyday users, Fusaka translates into a noticeably smoother experience across the Ethereum ecosystem. With the network now capable of handling far more data per block, activity is less likely to trigger sudden spikes in gas prices. This stability keeps average fees comfortably low on both Ethereum and its Layer 2 networks, creating a predictable environment where simple transactions, swaps, gaming interactions and on-chain social activity can all take place without worrying about high costs.

Fusaka also introduces meaningful improvements to how users interact with wallets and applications. The addition of support for secp256r1 signatures opens the door to device-native authentication, including fingerprint and facial recognition. This makes Ethereum wallets feel more like modern mobile apps and less like technical tools dependent on seed phrases. At the same time, the reduced bandwidth requirements enabled by PeerDAS make it easier for more people to run validator nodes from home, contributing to a healthier and more decentralized network. Altogether, Fusaka brings Ethereum closer to offering an experience that is fast, intuitive and accessible to users everywhere.

Conclusion

Fusaka marks a major milestone in Ethereum’s long-term scaling journey and reinforces the network’s commitment to a rollup-centric future. By combining PeerDAS, higher block capacity and user-focused improvements, the upgrade delivers a meaningful leap in performance without compromising decentralization. Rollups gain the room they need to scale aggressively, fees become more predictable for everyday users, and validators benefit from significantly lighter hardware requirements.

As Ethereum continues moving toward full Danksharding, Fusaka serves as an important bridge to the next generation of high-throughput blockchain infrastructure. It strengthens the foundation that future upgrades will build upon and positions Ethereum to support far more activity across decentralized finance, gaming, digital identity and emerging on-chain applications. With Fusaka now live, the network enters a new phase where scalability is no longer a distant goal but an evolving reality that users and developers can feel across the ecosystem.