Glossary
OpenSea
The original general-purpose NFT marketplace, launched 2017 — at peak handled most NFT trading volume; since challenged by Blur, Magic Eden, Tensor, and others.
OpenSea launched in late 2017 and rode the 2021 NFT cycle to become the dominant marketplace by an enormous margin. It supports multi-chain trading (Ethereum, Polygon, Arbitrum, Optimism, Base, Solana, and others) and offers the cleanest discovery / listing UX in the category.
Market share eroded sharply in 2022–2023 as Blur and other zero-royalty venues won the trader segment with token incentives and faster UX. The 2024 OS2 redesign + SEA token launch attempted to claw back relevance.