Ethereum BPO Hard Fork Raises Blob Limit to 21

Key Highlights

Ethereum’s blob limit was raised from 15 to 21 and the blob target from 10 to 14, allowing more data per block.
Blobs help layer‑2 rollups process transactions off-chain, reducing congestion and stabilizing fees.
Future upgrades may raise the gas limit to 80–200 million and add parallel processing, boosting speed and efficiency.

Ethereum’s network took another step toward higher throughput and lower fees today with the activation of its second Blob Parameter‑Only (BPO) hard fork. This upgrade is designed to to scale data availability without the complexity of a full-scale protocol overhaul, officially expands the “blob” limit available for Layer-2 (L2) networks.

This upgrade raised the blob limit from 15 to 21, allowing each block to carry more rollup data. The blob target was also increased from 10 to 14, guiding the network to operate efficiently under normal conditions.

Blobs are temporary data containers introduced by earlier upgrades to help layer‑2 rollups, such as Arbitrum, Optimism, Base and Mantle, bundle many transactions off the Ethereum mainnet.

Each blob can hold 128 kilobytes of data, so with the new limit, a block can handle around 2.6–2.7 MB of blob data. That extra space helps rollups publish transaction information more efficiently without overloading Ethereum’s core chain.

Why does this matter?

Rollups are where most Ethereum activity happens today. They process transactions off‑chain and then settle results back on Ethereum. Without enough data capacity, rollups compete for space, pushing up costs and congestion.

Increased blob size limits and target values enable a larger amount of data to be transmitted per block, reducing congestion and stabilizing fees. Already, data from the first BPO fork in December 2025 reflected smoother fees, so it appears to be an effective solution.

The distinction between the blob limit and blob target is important. The limit (now 21) is the hard maximum, the most blobs that can be used in a block. The target (now 14) is the ideal operating level developers aim for most of the time. Running constantly at the maximum could strain node bandwidth and storage.

Future scaling plans

The BPO was included in the overall scaling agenda of the Ethereum network. Christine Kim of Galaxy Digital and Nethermind developer Ben Adams expressed confidence in raising Ethereum’s block gas limit from 60 million to 75–80 million after the second BPO hard fork.

Later in 2026, a Glamsterdam hard fork may increase the gas limit to 200 million, implementing perfect parallel processing through Block Access Lists. This would enable Ethereum to process multiple transaction streams simultaneously, which would boost efficiency.

At the time of writing, Ethereum was trading at $3,216.59, showing a weekly gain of 8.02%, having moved above the $3,100–$3,150 zone that previously acted as resistance. This old resistance now serves as a strong support level, which may limit pullbacks.

The following significant resistance level may be around 3,350-3,400. The RSI being in the lower 60s indicates a healthy momentum for Ethereum without being overbought.

In summary, all these updates prove that the scaling of Ethereum is done slowly and cautiously, targeting regions where the scaling is much needed while maintaining the network as a decentralized entity. Rollups will be the greatest beneficiaries, and users should look forward to stable fees and a healthy network.