Lucía Peña
Ethereum developers have finalized the last stage of the Fusaka upgrade, completing a multi-phase rollout that significantly enhances data availability while demonstrating a more flexible approach to network upgrades.
The latest update reinforces Ethereum’s long-term strategy of scaling efficiently without relying solely on large, infrequent hard forks.
On Wednesday, Ethereum successfully synchronized the second “Blob Parameters Only” (BPO) fork scheduled for the Fusaka upgrade cycle. Rather than introducing sweeping protocol changes, BPO forks allow Ethereum to fine-tune specific network parameters in a controlled and modular way.
According to Ethereum developers, this approach enables the network to adjust capacity incrementally, reducing risk while testing higher throughput under real-world conditions.
Why BPO Forks Matter for Ethereum
Unlike traditional upgrades that bundle multiple changes into a single annual event, BPO forks allow targeted optimizations. Parameters such as blob limits can now be adjusted independently, making Ethereum more responsive to growing demand.
This phased rollout strategy helps the network safely increase load, ensuring stability while expanding capacity.
Blobs Explained: The Backbone of Layer 2 Scaling
Blobs were introduced with Ethereum’s Dencun upgrade in 2024 and serve as temporary data containers that allow Layer 2 rollups to publish transaction batches to Ethereum at a lower cost.
Also known as Binary Large Objects, blobs are retained for 18 days before being permanently deleted. This design keeps costs low while maintaining sufficient data availability for rollups to function securely.
Fusaka’s Focus on Data Availability
Out of the 13 Ethereum Improvement Proposals (EIPs) included in Fusaka, many targeted improvements to Ethereum’s data availability layer. One of the most notable upgrades was PeerDAS, which enables nodes to validate blob data using smaller samples instead of downloading full datasets.
Fusaka also introduced the BPO mechanism, laying the groundwork for gradual blob scaling over time.
Blob Limits Increase Again
The first BPO fork went live on December 9, shortly after Fusaka’s initial deployment. That update increased:
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Target blobs per block from 6 to 10
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Maximum blobs per block from 9 to 15
With Wednesday’s upgrade, Ethereum raised those limits again:
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Target blobs per block: 14
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Maximum blobs per block: 21
What This Means for Layer 2 Networks
Higher blob limits translate directly into more data availability for Layer 2 solutions. By steadily increasing per-block blob capacity, Ethereum is lowering data costs for rollups, helping keep Layer 2 transaction fees low even as usage continues to grow.
This incremental scaling model supports Ethereum’s broader goal of sustainable network growth, allowing the ecosystem to expand without sacrificing security or decentralization.
