OP Mainnet vs Sei

OP Mainnet (Optimism) is an optimistic rollup that batches transactions to Ethereum and relies on fraud proofs submitted during a seven‑day challenge window. The Bedrock upgrade in 2023 cut L1 calldata costs by 40 % and introduced multi‑proof modularity. ‘RetroPGF’ rounds redistribute protocol revenue to public‑goods builders, governed by the OP token‑holder Collective.

Sei is a parallelised Cosmos‑SDK Layer‑1 optimized for order‑book exchanges, using Twin‑Turbo consensus to reach 300–400 ms finality. Its built‑in matching engine lets dApps compose on a shared liquidity layer, and fee markets are denominated in SEI with bulk‑order discounts. The ‘V2’ upgrade adds EVM compatibility via SeiDB and WASM contracts side‑by‑side.