Glossary · Ethereum

Sequencer

A sequencer is a special type of node that collects, orders, and batches transactions from a Layer 2 network before submitting them to the main Ethereum blockchain.

What it is

Sequencers are critical components in Layer 2 scaling solutions, particularly rollups, designed to increase transaction throughput and reduce costs on Ethereum. They aggregate user transactions off-chain, compress the data, and then post a single, consolidated transaction representing many individual ones to the Layer 1 Ethereum chain. This batching process significantly reduces the amount of data and computation required on the mainnet.

In the market, sequencers are central to the efficiency and decentralization discussions around Layer 2s. Their role in transaction ordering can create opportunities for Maximal Extractable Value (MEV), as they control the sequence of transactions. Debates often focus on whether sequencers should be centralized for speed or decentralized for censorship resistance and security, impacting Layer 2 tokenomics and governance models.

Why it matters

Understanding sequencers helps retail investors evaluate the decentralization, security, and potential MEV risks associated with different Layer 2 projects they might use or invest in.

Reviewed under editorial standardsUpdated September 26, 2026Not investment advice