Ethereum blob limit bumps up to 21, boosting network scalability

Ethereum scalability was boosted on Wednesday with the second Blob Parameter-Only hard fork, raising the blob limit from 15 to 21, the first of many improvements aimed at scaling the Ethereum ecosystem in 2026.

The second BPO hard fork, which took effect on Wednesday at 1:01:11 UTC, further increases Ethereum’s data throughput by allowing more transactions to be batched via rollups.

The BPO hard fork also raised the blob target from 10 to 14, which is widely seen as the more important metric to watch, as consistently approaching the 21-blob limit could overload node bandwidth and storage.

One blob unit fits 128 kilobytes of data, meaning Ethereum can now store up to 2,688 KB in a single block.

Source: Terence Chan

Blobs help keep Ethereum mainnet steady

While blobs boost transaction throughput on Ethereum layer 2s, they also help stabilize gas fees on the Ethereum mainnet as the network becomes less congested.

YCharts data shows that Ethereum transaction fees have been far more stable since the first BPO hard fork on Dec. 9, 2025.

Change in Ethereum fees over the last 12 months. Source: YCharts

Gas limit raise also on the radar

Participants in the Ethereum All Core Developers meeting on Dec. 15 also discussed the idea of raising the network gas limit from 60 million to 80 million once the second BPO hard fork was implemented.

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Doing that would directly increase the number of transactions and smart contract operations that can fit in each Ethereum block — further boosting overall throughput while potentially lowering fees.

Glamsterdam hard fork is also focused on scalability

Later in 2026, the Glamsterdam hard fork will allow the gas limit to ratchet up to 200 million and introduce “perfect parallel processing.”

Perfect parallel processing will become feasible on Ethereum through Block Access Lists under Ethereum Improvement Proposal-7928, which seeks to transform Ethereum’s single-lane mode of transaction processing into a multi-lane highway, further increasing transaction throughput.

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