Which L2s saw blob fee spikes?

TLDR

Blob base fees on Ethereum jumped after the recent upgrade, so any rollup that posts blobs saw short?term cost spikes, notably Arbitrum (ARB), Optimism (OP Mainnet), and Base.

1. The blob base?fee rose roughly 1,500 from 1 wei, restoring a real fee market for L2 data posting. See the market update.
2. Rollups highlighted in coverage include Arbitrum, Base, and OP Stack chains as directly impacted by blob fee tuning and new capacity. See the ecosystem note.
3. Smaller L2s appeared most exposed near the switchover, while larger L2s like Arbitrum and Optimism were seen as better prepared. See the commentary.

Deep Dive

1. Network-Wide Fee Reset

Ethereum introduced a floor for blob base?fees tied to execution costs, ending the 1 wei regime and causing a sharp initial jump. Reporting cites a roughly 1,500 move (1 wei to 1,500 wei), which re?prices the cost that L2s pay to publish rollup data and reduces inelastic congestion behavior in the blob market. See the market update.

Beyond the price floor, blob capacity is scheduled to expand via incremental blob parameter only upgrades, which should help stabilize fees as supply rises. The official schedule lifts the target and max blobs per block in December and January. See the foundation post.

2. Which L2s Felt It

Any Ethereum L2 that posts EIP?4844 blobs was affected. Coverage and official notes repeatedly mention Arbitrum, Base, and OP Stack chains as key rollups in scope for the new blob capacity and fee mechanics. See the ecosystem note and the OP Stack teams update.

Practically, that means Arbitrum (ARB), Optimism (OP Mainnet), and Base all experienced the base?fee reset for blobs, with fee paths now governed by market demand plus the new floor and future capacity increases. The upgrades goal is to keep L2 fees low over time while aligning costs with resource usage. See the foundation post.

3. Preparedness and Divergence

Commentary suggests larger L2s with mature infra (for example, Arbitrum and Optimism) may adapt faster to the new blob fee dynamics, while smaller rollups could feel more pressure when blob prices rise. See the commentary.

As capacity steps up in December and January, differences should narrow, but short bursts of congestion can still produce spikes before markets equilibrate. The broad intent of the upgrade is to create a functioning, stable blob fee market across all L2s. See the foundation post.

Conclusion

Blob base?fees rose across Ethereum, so L2s that publish blobs all saw a spike, with Arbitrum, Optimism, and Base explicitly called out in coverage. The schedule to raise blob capacity should reduce future spikes and make costs more predictable as the market for blob space matures.