OpenSea

OpenSea is a self-custody NFT marketplace for browsing collections, listing items, making offers and accepting bids from a connected wallet. It uses Seaport for marketplace orders, while the wallet holder keeps control of assets until an onchain order is fulfilled.

Seaport separates an order from its settlement

A Seaport order states what its maker offers and what they expect in return. A listing or bid can be visible before anyone accepts it; when eligible orders are fulfilled, the NFT and payment settle to their recipients in the same onchain transaction. That distinguishes advertising an order from the later transfer of both sides of the trade.

OpenSea supports fixed-price listings plus offers for an item, selected items, a collection or a defined collection trait. A collection offer can be accepted by the first holder of any eligible item, while a trait offer narrows eligibility. Bulk tools collect several orders for signing, and private orders name the buyer address that may fulfil them.

Order controls and a broad chain footprint

An onchain cancellation is immediate and irreversible but costs gas. Removing an order from OpenSea’s offchain order book costs no gas, yet does not change its blockchain state. EVM offers use WETH: a buyer signs the offer and Seaport verifies still-valid orders when a holder accepts.

OpenSea supports NFTs across Ethereum, Polygon, Arbitrum, Optimism, Avalanche C-Chain, Zora, Base, Blast and a wider group of EVM and adjacent chains. It supports Solana token swaps but not Solana NFTs. The marketplace is broad, but currencies, wallet actions and gas needs still follow the chain and collection involved in a particular trade.

Creator drops and conditional resale earnings

OpenSea Studio lets a creator deploy a SeaDrop-compatible collection, choose its identity and chain, upload metadata, set a mint schedule and publish a drop page. Collection owners can set a payout address and preferred earnings percentage, but that setting alone can be optional at resale: a seller may include, reduce or omit it on collections without compatible enforcement.

ERC721-C and ERC1155-C compatible collections can enforce creator earnings through Seaport hooks, so the transfer fails unless the fee condition is met. Magic Eden is a relevant alternative for Solana-focused trading, bulk inventory management and curve-based NFT pools. OpenSea’s sharper distinction is Seaport order types and a much wider supported NFT-chain footprint, along with Studio’s collection-and-drop tooling.