OpenSea

OpenSea has not been directly hacked, but it suffered two notable security incidents. In February 2022, a phishing attack tricked 32 users into signing malicious transactions, resulting in roughly $1.7M worth of NFTs stolen. In June 2022, a Customer.io employee leaked 1.8 million user email addresses that had been shared with the email vendor. Neither incident compromised OpenSea's smart contracts or user wallets directly.

OpenSea is a non-custodial platform, meaning it never holds your funds — risk is limited to what you approve on-chain. Its core trading logic runs on the Seaport protocol, which has been audited by Halborn and other security firms. OpenSea also runs a public bug bounty program. The main risks are phishing attempts, malicious NFT listings, and inadvertently signing harmful wallet approvals — using a hardware wallet and reviewing every signature are recommended precautions.

No. OpenSea is non-custodial: your assets remain in your own external wallet (MetaMask, Ledger, Coinbase Wallet, etc.) at all times. OpenSea never takes custody of your NFTs or ETH. When you buy or sell, the Seaport smart contract executes the swap directly between wallets. This means OpenSea cannot freeze or return your assets if you are phished — custody and security responsibility stays entirely with you.

OpenSea supports a broad range of chains including Ethereum, Polygon, Arbitrum, Avalanche, Base, BNB Chain, Optimism, Zora, and Solana, among others. Supported chains expand over time — the official OpenSea documentation is the most accurate source. Cross-chain trading is not native; each listing is settled on the chain where the NFT lives.

OS2 is the relaunched version of OpenSea, rolled out in 2024. It introduced a revamped interface, improved creator royalty tooling, and expanded chain support. Alongside OS2, OpenSea launched the SEA token — its platform utility and governance token, distributed in part via an airdrop to historical users. The relaunch was OpenSea's response to competitive pressure from rivals such as Blur and Magic Eden, which had eroded its market-share dominance.