What Is OpenSea? How the NFT Marketplace Works

What you can do on OpenSea

OpenSea's core use is still NFTs, but the product now covers several activities:

• Buy NFTs at a listed price or place offers on single items or whole collections.
• Sell NFTs by listing at a fixed price or accepting offers. Listings from other marketplaces are aggregated into OpenSea's view of a collection.
• Create a collection or a timed drop in OpenSea Studio. Minting an NFT on OpenSea means deploying or using a contract through Studio and paying the network's gas fee.
• Swap tokens across supported chains, a feature introduced with OS2.
• Use the mobile app, which supports email sign-up. OpenSea notes that some app features roll out in phases and may not be available to every user.
• Build with the API. Developers can query listings, collections and orders through the OpenSea API; since July 2026 the API also supports wallet-based authentication.

OpenSea's site navigation also lists a beta "Perpetuals" product. Its terms do not yet describe it, so its availability and rules should be checked in the app before use.

Accounts, login and wallets

On OpenSea, a wallet address is your identity. There are two ways in:

1. Connect an external wallet you already control.
2. Sign up with an email. A six-digit code logs you in, and OpenSea's partner Privy automatically creates an EVM wallet and a Solana wallet for the account. According to OpenSea's help center (June 2026), these wallets are self-custodial and do not require a separate seed phrase to start. Addresses created this way are permanently tied to that email login and cannot be moved to another email account.

Either way, the Terms of Service (updated October 7, 2026) state that OpenSea "does not operate, maintain, or have any custody or control over wallets or their contents." OpenSea cannot reverse a transaction you sign or recover assets sent to the wrong address. OBOL's wallets 101 and seed phrase security guides cover the basics.

Fees: what a sale actually costs

An NFT sale on OpenSea involves up to three separate charges:

The platform fee rose from 0.5% to 1% on September 15, 2025, per OpenSea's developer changelog, to fund its rewards pool ahead of the planned token. *Illustration (not a quote):* selling an NFT for 1 ETH in a collection with an enforced 5% creator fee would leave the seller about 0.94 ETH before gas.

Token swaps carry their own fees, shown in the swap quote. After postponing the SEA token in March 2026, OpenSea announced a 0% swap fee for 60 days starting March 31, 2026; current swap pricing should be read from the quote screen. Gas and third-party payment processor fees are not refundable by OpenSea.

How creator earnings work

Creator earnings on OpenSea are either optional, meaning the buyer or seller decides whether to pay, or enforced, meaning they are paid on every sale. According to OpenSea's help article (January 2026), only collections created in OpenSea Studio after April 2, 2024, or custom contracts compatible with the ERC721-C or ERC1155-C standards, can enforce earnings. Enforcement limits where the NFT can be sold to OpenSea and marketplaces using Limit Break's Payment Processor, such as Magic Eden. If a creator sets a higher rate on OpenSea than elsewhere, OpenSea may lower it to match.

Supported blockchains

OpenSea's chain compatibility page lists networks including Ethereum, Polygon, Arbitrum, Optimism, Avalanche, Base, Zora Network, Blast, Sei, B3, Berachain, Flow, ApeChain, Soneium, Shape, Unichain, Ronin, Abstract, Solana, GUNZ, HyperEVM, Somnia, Monad, MegaETH and Robinhood Chain as of October 2026. The page's summary also names AnimeChain, Stable Chain and Arc, which are missing from its main list, so confirm a specific chain inside the app. An NFT on one chain cannot be bought with funds on another without bridging or an OpenSea cross-chain purchase route; OBOL's bridging guide explains the risks of moving assets between networks.

Staying safe on OpenSea

Most losses on NFT marketplaces come from the user's wallet, not the marketplace contract:

• Signature phishing. Fake mint sites and "airdrop claim" pages ask users to sign listings or approvals that let an attacker take NFTs for nothing. Read every signature request.
• Unlimited approvals. Approving a collection or token for trading grants ongoing permission; revoke unused approvals.
• Copycat collections. Search results can include knockoffs with similar names and art. Check the collection's contract address and the creator's verified links.
• Stolen items. The terms prohibit trading stolen NFTs, and OpenSea may restrict an item's visibility or transferability under its Prohibited Content and Disputed Items Policy. It does not rule on ownership disputes.
• Manipulated activity. The terms ban manipulating prices, rankings or "fake or misleading liquidity." Sales history can still include wash trades; see crypto wash trading explained.

The SEA token and rewards

As of October 2026, OpenSea has no live token. OpenSea announced the SEA token alongside OS2 and scheduled its launch for March 30, 2026. On March 16, 2026, CEO Devin Finzer postponed it, citing "challenging" market conditions, and gave no new date (DL News). The OpenSea Foundation, which is handling the token, said it would set a new timeline later. Alongside the delay, OpenSea ended its Treasure rewards program with a final wave and offered fee refunds for Seasons 3–6 to users willing to forfeit their accumulated Treasure.

Rewards earned on OpenSea, including XP points and Treasure Chests, are non-transferable, have no cash value and may expire, according to the terms. Any website or message selling "SEA" tokens or offering an "OpenSea airdrop claim" outside official channels should be treated as a scam.

Company background and legal record

OpenSea was founded in December 2017 and went through Y Combinator's Winter 2018 batch. In January 2022 it raised $300 million led by Paradigm and Coatue at a $13.3 billion valuation, TechCrunch reported. That valuation predates the NFT market downturn and is not a current figure.

Several events shaped its record:

• 2022 incidents. OpenSea dealt with a listing bug, a phishing attack using the Wyvern order protocol in February 2022, and a June 2022 leak of user email addresses by an employee of its email vendor, Customer.io.
• Insider trading case. Former product manager Nathaniel Chastain was convicted of wire fraud and money laundering in May 2023 in what was described as the first digital-asset insider trading case. The US Court of Appeals for the Second Circuit overturned the conviction on July 31, 2025 (The Block).
• SEC investigation. OpenSea received a Wells notice from the US Securities and Exchange Commission in August 2024 over whether NFTs on the platform were securities. In February 2025 OpenSea said the SEC had closed its investigation without recommending enforcement action (The Block).
• OS2. In 2025 OpenSea relaunched as OS2, adding token trading and cross-chain purchases.

Who can use OpenSea

The terms require users to be at least 18; users aged 13 to 17 may use OpenSea only through a parent or guardian's account. People located in, resident in or organized under the laws of a US-sanctioned country, and sanctioned individuals, are barred. The terms are governed by New York law, with most disputes going to JAMS arbitration and remaining court matters to Miami-Dade County, Florida. Liability is capped at the greater of $5,000 or what OpenSea earned from the relevant transaction.

Support and official channels

OpenSea's help center at support.opensea.io has guides on accounts, buying and selling, swaps, drops, Solana NFTs and user safety; platform incidents are posted at status.opensea.io. Treat any direct message asking for a seed phrase, a private key or a "verification" signature as a scam.

Official channels:

• Website: opensea.io · Help center: support.opensea.io
• Developer docs: docs.opensea.io
• Blog: opensea.io/blog
• X: x.com/opensea
• LinkedIn: linkedin.com/company/opensea-io
• GitHub: github.com/ProjectOpenSea

OBOL's assessment of the marketplace is in the OpenSea marketplace review, and its analytics features are covered in the OpenSea analytics review. Other platforms are compared on the NFT marketplaces hub.