What is OP Mainnet? June 16, 2023 18:42 Updated OP Mainnet is an EVM equivalent Optimistic Rollup chain. It's designed to be fast, simple, and secure. Related articles Why use OP Mainnet? How does OP Mainnet work? Is OP Mainnet a sidechain? What is a rollup? How do transaction gas fees on OP Mainnet work?