Ethereum's Fusaka upgrade, which went live on December 3, 2025, was designed to scale the network's data capacity rather than deliver a magical fee reset across the board. The upgrade introduced PeerDAS (peer data availability sampling) and enabled Blob Parameter Only forks that gradually raised blob targets from 6 per block toward 14 and beyond, creating cheaper rollup data posting and more room for Layer 2 networks to operate efficiently.

What Exactly Did Fusaka Change for Ethereum Users?

The Ethereum upgrade 2026 story centers on capacity and scaling, not a universal fee reduction. Fusaka followed Pectra in 2025 and included execution-layer and consensus-layer changes aimed at improving Layer 1 performance, blob throughput, and the user and developer experience. The headline feature was PeerDAS, formally known as EIP-7594, a data-availability sampling design for blobs that fundamentally changed how validators handle transaction data.

Before PeerDAS, validators had to download and process every blob of data directly as rollups posted more information to Ethereum. After Fusaka, validators can sample blob data instead of downloading every blob in full, which lets Ethereum scale data availability without requiring every normal validator to behave like a data-center node. This distinction matters because it removes a major bottleneck that could have forced the network to centralize around larger, better-resourced operators.

The upgrade also introduced EIP-7892, known as Blob Parameter Only forks, or BPOs. This mechanism lets Ethereum change blob parameters such as the target, maximum, and base-fee update fraction without waiting for another full named hard fork. It's a practical tool that enables the network to adjust capacity incrementally rather than in large, disruptive jumps.

Where Are Ethereum Fees Actually Lower After Fusaka?

Ethereum fees now operate as two separate conversations. Layer 1 gas is what you pay to transact directly on mainnet; blob fees are what rollups pay to publish transaction data back to Ethereum. Fusaka is mainly about the second bucket. According to ethereum.org in 2026, higher blob throughput directly benefits Layer 2 rollups because their transaction fees can fall when blob capacity scales. That's why the most visible effect for ordinary users is more likely on Arbitrum, Optimism, Base, zkSync, Starknet, Linea, and other rollups than on a plain ETH transfer on mainnet.

Mainnet fees were already low in early 2026. Ethereum.org reported on May 5, 2026, that Etherscan standard gas was around 0.15 gwei and that daily averages had been near 0.5 gwei through April 2026. On May 7, 2026, ethereum.org said a basic ETH transfer could cost under a cent at around 0.15 gwei, with typical recent days in the low single-digit cents. A basic ETH transfer uses 21,000 gas, which at 0.15 gwei equals 3,150 gwei, or 0.00000315 ETH. If ETH were $3,000 in 2026, the fee would be about $0.00945.

However, cheaper blob space doesn't guarantee the fee you see in your wallet drops one-for-one. Rollups have their own sequencer pricing, congestion, proof costs, and margin choices. If a Layer 2 keeps more of the savings, users may see only part of the blob-capacity benefit.

How Did Blob Capacity Increase Step by Step?

Fusaka did not instantly flood Ethereum with blob capacity on activation day. Ethereum.org says the blob count remained unchanged immediately after Fusaka, with increases intended to happen step by step through BPOs. That matters because fee relief from extra capacity arrives in stages, not as a single switch flip. The first planned BPO steps after December 9, 2025 raised the per-block blob target and maximum from 6 and 9 to 10 and 15, then to 14 and 21. An Ethereum Foundation checkpoint listed BPO fork 2 for January 7, 2026 at 01:01 UTC with target blobs of 14 and maximum blobs of 21.

Each blob can carry up to 128 KB of data. Moving from a target of 6 blobs to 14 blobs means target blob data per block rises from 768 KB to 1,792 KB, which represents about 2.33 times the target data capacity at that stage. Ethereum.org also described PeerDAS as delivering roughly an order-of-magnitude increase in data-availability capacity for Layer 2s, and said Fusaka plus BPOs enabled an 8x increase in theoretical blob capacity.

• Pre-BPO baseline (2025): 6 target blobs and 9 maximum blobs, delivering 768 KB of target data per block
• BPO step 1 (from December 9, 2025): 10 target blobs and 15 maximum blobs, delivering 1,280 KB of target data per block
• BPO fork 2 (January 7, 2026): 14 target blobs and 21 maximum blobs, delivering 1,792 KB of target data per block
• Reported theoretical direction (2026): Up to 48 blobs reported by ethereum.org, which would deliver 6,144 KB of target data per block

Did Staking Economics Change With Fusaka?

A common misunderstanding is that Fusaka rewired staking rewards. It didn't. The major staking-economics change was Pectra, the upgrade that preceded Fusaka, and that distinction matters if you run validators or evaluate staking services. Pectra's EIP-7251 raised the maximum effective balance from 32 ETH to 2,048 ETH. It also enabled validator consolidation and auto-compounding through 0x02 compounding validators.

A June 2026 arXiv paper reported that Ethereum's beacon chain had more than 920,000 active validators and identified the Pectra change as the move that lifted the maximum stake per validator. For large stakers, consolidation can reduce operational clutter. Instead of managing many 32 ETH validators, a staker can move toward fewer validators with larger effective balances. However, that option only makes sense if you understand validator operations, withdrawal credentials, client diversity, and the migration process; it's not a casual wallet setting.

For solo stakers near 32 ETH, the Ethereum upgrade 2026 fee debate is more relevant than the max-balance change. You don't suddenly need 2,048 ETH, and you don't need to convert your ETH after Fusaka. Ethereum.org says ETH holders do not need to take action and balances remain accessible in their existing form.

How Should Builders and App Teams Respond to Fusaka?

For builders, the Ethereum upgrade 2026 takeaway is that Layer 2-first design has become more defensible. Dencun introduced blobs, Pectra improved wallet and staking capabilities, and Fusaka expanded the data-availability path that rollups depend on. Ethereum.org's May 2026 builder post said those upgrades changed assumptions about Layer 1 costs and wallet capabilities. If you're designing an exchange, game, payment app, or tokenized asset workflow, don't price your user experience around mainnet-only execution unless you have a strong reason.

• Measure actual Layer 2 fees: Track the real transaction costs your users pay on rollups in 2026, not only the Ethereum blob fee component, since sequencer and other costs add up
• Check rollup pass-through rates: Verify whether your rollup passes blob savings through to users during busy periods, since some operators may retain more of the savings
• Separate cost categories: Break down Layer 1 settlement costs from sequencer fees, proof costs, bridge costs, and withdrawal costs to understand the full fee picture
• Test wallet flows: Run through wallet flows after Pectra-era account and staking changes if your app touches those features, since user experience may have shifted

Tokenized funds and real-world asset platforms, for example, need predictable settlement and compliance flows; the cost side connects naturally with questions around tokenized real-world assets. The key insight is that Fusaka didn't make Ethereum itself cheaper for most users, but it created the infrastructure for rollups to pass savings downstream.