Ethereum's Fusaka Upgrade and PeerDAS: How Blob Scaling Cut Layer-2 Fees

Ethereum's whole scaling strategy is to push most activity onto Layer-2 rollups and make the base layer dirt cheap for them to post data to. The Fusaka upgrade, activated in December 2025, was the biggest step yet in that plan. Its headline feature, PeerDAS, changed how the network stores the data rollups rely on, unlocking roughly eight times more capacity and helping drive many Layer-2 fees below two cents. If you have noticed cheaper rollup transactions in 2026, Fusaka is a big part of why.

Key takeaways

• Fusaka, activated December 2025, introduced PeerDAS, a data-availability sampling system that lets nodes verify blob data without storing all of it.
• This unlocked roughly 8x more data throughput for rollups, the main driver of cheaper Layer-2 fees.
• Blob capacity can now scale gradually between hard forks through scheduled parameter bumps, rather than waiting for the next big upgrade.
• Major Layer-2 fees now sit consistently below $0.02 thanks to the extra blob space.
• Fusaka built on Pectra (May 2025), which doubled blob throughput and introduced smart-account features.

What blobs are, briefly

In 2024, Ethereum added "blobs," a cheap, temporary data space designed specifically for rollups to post their transaction data. Rollups execute transactions off-chain and then publish compressed data back to Ethereum so anyone can verify it. Blobs made that publishing far cheaper than using regular transaction space. The catch was capacity: every node had to download and store each blob in full, which capped the network at a small number of blobs per block.

That storage requirement was the bottleneck Fusaka set out to remove.

PeerDAS changes the rules

PeerDAS stands for peer data-availability sampling. Instead of every node storing every blob completely, nodes now sample small pieces of the data and rely on cryptographic guarantees that the rest is available. If enough nodes can each retrieve their samples, the network can be confident the full data exists without any single node holding all of it.

Because nodes no longer carry the full burden, the network can support many more blobs per block. Fusaka also decoupled blob capacity from major upgrades: through scheduled parameter changes (sometimes called Blob Parameter Only forks), the limit can be raised gradually as the network proves it can handle more, rather than waiting for the next hard fork. The first such increases were planned to lift blob capacity in steps after activation, so the practical effect of Fusaka keeps compounding over the months that follow rather than landing all at once.

The clever part of data-availability sampling is the math underneath it. Blob data is encoded with erasure coding, which spreads the information so that the full data can be reconstructed even if a large fraction of the pieces is missing. That property is what makes random sampling trustworthy: if a node successfully grabs its handful of random samples, the probability that the rest of the data is unavailable becomes vanishingly small. A would-be attacker cannot hide a small slice of withheld data, because the sampling would catch it with overwhelming likelihood. This is how Ethereum can let nodes check "a little" and still be confident the whole blob exists, the core trick behind the entire scaling gain.

Why fees fell

More blob space means rollups compete less fiercely for a scarce resource, so the cost of posting data drops. Since data posting is a major component of a rollup's cost, cheaper blobs translate fairly directly into cheaper Layer-2 transactions. By 2026, transaction fees on major Layer-2 networks consistently sit below two cents. Fusaka also refined blob fee pricing so the base fee behaves more sensibly when demand is low, smoothing out the cost curve.

If you want the underlying mechanics of why rollups are cheaper than the base layer in the first place, our Layer-2 gas fees explainer covers that, and the smart-account features that arrived in the prior Pectra upgrade are detailed in our EIP-7702 smart accounts piece.

How it fits the roadmap

Fusaka is part of a deliberate sequence, each upgrade building on the last. Here is the recent timeline that got Layer-2 fees where they are today:

Upgrade	Date	Key scaling change
Dencun	March 2024	Introduced blobs (proto-danksharding), the first cheap data space for rollups
Pectra	May 2025	Doubled blob throughput, added smart-account features (EIP-7702)
Fusaka	December 2025	PeerDAS (EIP-7594), roughly 8x more blob capacity
Post-Fusaka bumps	2026 onward	Scheduled blob-limit increases between hard forks

The Ethereum Foundation's 2026 priorities continue down this path, focused on scaling data availability further while keeping the network decentralized enough that ordinary consumer hardware can still run a node. The goal stays consistent: keep the base layer lean and let rollups carry the volume.

What this means for you

• If you transact on rollups (Arbitrum, Base, Optimism, and others), you are already paying less; no action needed.
• If you bridge or move funds, cheaper data costs make small Layer-2 transactions far more practical than they were in 2023.
• If you run a node, PeerDAS means you sample data rather than store every blob, so the storage burden did not balloon with capacity.
• If you build a rollup, the decoupled blob limits give you a clearer runway as capacity scales in scheduled steps.

For the underlying mechanics of why rollups are cheaper than the base layer, our Layer-2 gas fees explainer covers it, and the wider 2026 roadmap is laid out in our Fusaka and Glamsterdam roadmap piece.

Frequently asked questions

What is the single most important thing Fusaka did?

It brought PeerDAS to mainnet, which lets nodes sample blob data instead of storing all of it, unlocking roughly 8x more rollup data capacity without raising node hardware requirements.

Did Fusaka make Ethereum mainnet transactions cheaper?

Its main effect is on Layer-2 rollups, where fees fell below two cents. Base-layer (Ethereum mainnet) fees are driven more by overall demand for block space than by blob capacity, so they did not see the same drop.

Can blob capacity keep growing now?

Yes. Fusaka decoupled blob limits from hard forks, so capacity can be raised in scheduled parameter bumps as the network proves it can handle more, rather than waiting for the next big upgrade.

Do I need to do anything as a user?

No. The benefit shows up automatically as cheaper transactions on rollups. You do not need to change wallets, networks, or settings to enjoy lower Layer-2 fees.

What is the difference between a blob and a regular transaction?

A blob is a large chunk of temporary data attached to a block, designed specifically for rollups to post their compressed transaction data cheaply. Unlike regular transaction calldata, blobs are deleted after about 18 days, which is what keeps them cheap.

This article is for general information and is not financial advice.