Ethereum Raises Blob Limit to 21 in Second BPO Hard Fork
On Jan. 7, 2026, Ethereum executed its second BPO hard fork, raising the per-block blob limit from 15 to 21. That lift increases maximum data capacity per block to about 2.6 MB, allowing more blobspace to be included in each block. Network validators and clients processed the change as part of the ongoing scaling roadmap, and the adjustment was applied without reported disruption to consensus.
The higher blob limit should directly benefit rollups and data-heavy dapps by expanding on-chain data availability and easing pressure on calldata markets, which can translate into lower settlement costs and improved throughput. There is a trade-off: nodes and validators will see larger average block sizes, which raises bandwidth and storage demands. Still, the upgrade is a clear step toward accommodating growing L2 activity and sustaining cheaper, faster settlement on Ethereum.