Arbitrum vs Sei

Arbitrum One and Nova are optimistic rollups using Nitro fraud proofs that compress transactions into calldata submitted to Ethereum. The Orbit toolkit lets projects deploy their own Arbitrum Orbit chains with configurable permissions. ARB token governance manages the 3 000‑plus validator whitelist and a 1 billion‑dollar ecosystem grant fund.

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.