Sequencer
Last updated 17 October 2026Last verified 17 October 2026
What is a sequencer in a Layer 2?
The centralized entity that orders transactions on most optimistic rollups and ZK rollups. A sequencer can delay or censor transactions, creating a trust assumption the base chain does not have. Most L2s are working toward decentralized sequencers, but most production sequencers are still operated by a single entity.
TradFi equivalentThe role an exchange matching engine plays, without the fair-access and non-discrimination obligations an exchange operates under, and free to pay itself out of the ordering.