When is ETH blob upgrade?

TLDR

Ethereum (ETH) will activate its next blob upgrade (BPO?2) on 7 Jan 2026 (UTC), per multiple week?ahead summaries. See the CoinDesk update.

1. BPO?2 raises the blob target to 14 and maximum to 21 per block to expand rollup data capacity. Details.
2. It follows BPO?1, which lifted capacity to about 15 blobs per block. Summary.
3. More blob supply could lower Layer 2 fees, but relief depends on demand and stability. Context.

Deep Dive

1. Date

The upgrade is scheduled for 7 Jan 2026. This timing appears in multiple credible week?ahead roundups covering crypto events and macro releases, including a CoinDesk report and a Yahoo Finance brief.

2. What Changes

BPO?2 is a minimal, configuration?only upgrade that raises the per?block blob target to 14 and the maximum to 21, expanding data capacity for rollups without a broader hard fork, per the CoinDesk update. It follows BPO?1, which increased capacity to around 15 blobs per block as noted in the Yahoo Finance brief.

1. Target 14, max 21 blobs per block in BPO?2. Reference.
2. BPO?1 raised capacity to about 15 blobs per block. Reference.

3. Implications

Expanded blob capacity can pressure blob fees lower, which many Layer 2s pass through into end?user transaction costs. The effect is conditional on demand and network stability, as highlighted in the NewsBTC analysis.

1. If demand rises as fast as capacity, fee relief could be muted. Context.
2. Watch Arbitrum, Optimism, and Base in the days after the upgrade for realized fee changes. Summary.

Conclusion

The ETH blob upgrade BPO?2 lands on 7 Jan 2026 and increases blob capacity significantly. If network demand and stability cooperate, Layer 2 users could see lower costs, with the biggest benefits showing up on high?traffic rollups soon after the change.