Glossary
Based Rollup
A rollup whose sequencing is performed directly by Ethereum L1 proposers — no dedicated sequencer set, no centralization in transaction ordering.
A "based" rollup, proposed by Justin Drake in 2023, delegates sequencing to whichever Ethereum L1 proposer is currently producing a block. There is no separate L2 sequencer; the L1 proposer includes L2 transactions on their own, in L1 block order.
The design eliminates sequencer centralization in exchange for some loss of L2 UX (no sub-second confirmations unless combined with pre-confs). Taiko was the first based rollup to launch on mainnet.