Ethereum Activates BPO #2 Upgrade Boosting Blob Capacity

Ethereum (ETH) has activated its second Blob Parameters Only fork, known as BPO #2, completing the . The change increases how much rollup data Ethereum can carry per block, directly targeting Layer 2 costs rather than base-layer features.

With the upgrade finalized this week without any issues, ETH is now transitioning toward smaller, parameter-based scaling steps instead of infrequent, high-risk hard forks.

BPO #2 raises blob limits, the temporary data packet rollups used to post transaction batches to mainnet. The blob target per block increased to 14 from 10. The maximum blob limit rose to 21 from 15. These limits define how much data rollups can publish in each block before fees rise.

More blob space means rollups face less competition for data availability. That directly reduces fee pressure during periods of high activity. Interestingly, blobs are now one of the main cost drivers for Layer 2 networks such as Base, Arbitrum, Optimism, and several zero-knowledge rollups.

When blob space is tight, rollups bid against each other and fees spike. When blob capacity expands, costs stabilize. On-chain data shows current blob usage is well below the new limits. Ethereum is scaling ahead of congestion rather than reacting to it.

The Fusaka upgrade was deployed in phases. BPO #1 activated on December 9, laying the groundwork by raising blob limits for the first time after Dencun.

BPO #2 applied the final parameter increases days later. This staged approach lets developers observe real network behavior before widening capacity further. Client teams implemented the changes without requiring action from users or most application developers.

For end users, the impact shows up on Layer 2. Cheaper data posting allows rollups to lower transaction fees for swaps, transfers, NFT mints, and gaming activity.

At the network level, the upgrade reinforces Ethereum’s rollup-first scaling path. Instead of pushing execution onto mainnet, Ethereum is expanding data availability and letting rollups handle execution.