OpenSea Complete Guide
OpenSea is the world's largest NFT marketplace with $2.8 billion monthly volume in 2026 (down from $5 billion peak in 2021). Founded in 2017, survived the 2022 crash, cut fees 50% to compete, and remains dominant despite Blur's challenge. Here's everything you need to know.
In February 2022, OpenSea users lost $3.2 million worth of NFTs in a phishing attack. Hackers sent emails pretending to be OpenSea, asking users to "migrate" their listings. Those who signed the malicious transaction lost their NFTs instantly. OpenSea has never and will never ask you to sign transactions via email.
OpenSea: Complete History
2017-2020: Slow Start
OpenSea launched in 2017 as the first NFT marketplace. Mostly CryptoKitties and obscure art. Few users. Survived through crypto winter when most projects died.
2021: Explosion
NFT boom made OpenSea a unicorn. $14 billion valuation. Processing billions in monthly volume. 2.5% fee on every transaction = massive revenue. Bored Apes, CryptoPunks, and celebrity NFTs all traded here.
2022: Crisis Year
- January: $3 billion monthly volume (peak)
- February: $3.2 million phishing attack hits users
- August: Made creator royalties optional (creator backlash)
- December: Volume down 90% from peak
2023: Fighting Back
Blur launched with 0% fees and aggressive marketing. OpenSea responded by cutting fees from 2.5% to 0% temporarily (February 2023), then settled at 2.5%. Introduced OpenSea Pro for advanced traders.
2026: Current State
Still the largest NFT marketplace but sharing market with Blur and Magic Eden. $2.8B monthly volume. 2.5% marketplace fee. Royalties optional. Supports Ethereum, Polygon, Solana, Arbitrum, Optimism, Avalanche, and Base.
| Metric | 2021 Peak | 2026 Current | Change |
|---|---|---|---|
| Monthly Volume | $5 billion | $2.8 billion | -44% |
| Daily Active Users | 350,000 | 125,000 | -64% |
| Collections Listed | 2 million | 8 million | +300% (most dead) |
| Marketplace Fee | 2.5% | 2.5% | No change |
Getting Started with OpenSea
Connect Your Wallet:
- Go to opensea.io (type directly!)
- Click wallet icon in top right
- Select MetaMask (or your wallet)
- Approve connection in wallet popup
- You're connected!
Fake OpenSea sites steal your NFTs. ALWAYS type the URL directly or use a bookmark. Never click OpenSea links from emails, Discord, or social media.
Understanding the Interface:
- Explore - Browse trending collections
- Stats - See market data and rankings
- Profile - View your NFTs and activity
- Search - Find specific collections or NFTs
Supported Networks:
- Ethereum (most NFTs)
- Polygon (cheap minting/trading)
- Solana (separate ecosystem)
Buying NFTs on OpenSea
Method 1: Buy Now
- Find NFT you want to buy
- Check the "Buy now" price
- Click "Buy now"
- Review transaction details
- Confirm in your wallet
- Pay NFT price + gas fees
- NFT transfers to your wallet!
Method 2: Make an Offer
- Click "Make offer" on any NFT
- Enter your offer amount (in WETH)
- Set expiration date
- Sign the offer (no gas fee)
- If seller accepts, trade executes
ETH: Used for "Buy now" purchases
WETH (Wrapped ETH): Used for offers and auctions
You can wrap/unwrap ETH for free on OpenSea.
Before Buying - Checklist:
- ✓ Blue verification checkmark
- ✓ Reasonable floor price and volume
- ✓ Active trading history
- ✓ Official links match project's social
- ✓ Contract address verified
Selling NFTs on OpenSea
Listing Your NFT:
- Go to your Profile
- Click on NFT you want to sell
- Click "List for sale"
- Choose listing type:
- Fixed price - Set your price
- Timed auction - Bidding
- Set your price
- Set duration (1 day - 6 months)
- Sign listing (gas-free on most networks)
OpenSea Fees Breakdown 2026:
| Fee Type | Amount | Who Pays | Notes |
|---|---|---|---|
| OpenSea Fee | 2.5% | Seller | Down from 2.5% (never changed) |
| Creator Royalty | 0-10% | Seller (optional) | Was mandatory, now optional since 2022 |
| Gas (listing) | $0 | Free | Lazy listing (gas paid on sale) |
| Gas (buying) | $10-50 | Buyer | Varies by network congestion |
| WETH conversion | $5-20 | User | Only for offers/bids |
Real Fee Example:
You sell an NFT for 1 ETH ($3,000):
- Gross sale: 1 ETH ($3,000)
- OpenSea fee (2.5%): -0.025 ETH ($75)
- Creator royalty (5% if you pay): -0.05 ETH ($150)
- Net received: 0.925 ETH ($2,775)
- Total fees: 7.5% ($225)
Royalty Controversy Impact
When OpenSea made royalties optional in August 2022, creator economics collapsed. Before 2022, an artist earning 5% on secondary sales of a 10,000 piece collection at 0.1 ETH average could make 50 ETH ($150k) passively. After royalties became optional, most buyers stopped paying them. Artists lost this income stream. Some collections enforce royalties at smart contract level, but most ERC-721 NFTs cannot.
- Check floor price of collection
- Price slightly below similar listings for faster sale
- Rare traits = price above floor
- Don't price too high or you'll never sell
Staying Safe on OpenSea
Red Flags - Don't Buy:
- No blue checkmark on popular collections
- Price way below floor - often fake
- Very new collection copying famous art
- Suspicious offers from unknown buyers
- Hidden content warning - usually scam
OpenSea-Specific Scams With Real Losses
1. February 2022 Phishing Attack ($3.2M Lost)
Hackers sent emails pretending to be from OpenSea about "migrating listings." Email had OpenSea branding and looked legitimate. Users who clicked and signed the transaction gave attackers "setApprovalForAll" permission, allowing theft of entire NFT collections. 17 users lost high-value NFTs including Bored Apes and Decentraland parcels.
How to avoid: Never sign transactions from email links. OpenSea never asks you to sign anything via email.
2. Fake Collection Attack ($620k Lost in 2022)
Scammers created a fake "Bored Ape Yacht Club" collection with identical art but different contract address. Listed NFTs at 50% below floor price. Buyers who didn't verify the contract address bought worthless copies.
How to avoid: Always check the blue verification badge and verify contract address on Etherscan.
3. Fake OpenSea Support (Ongoing)
Scammers create Twitter/Discord accounts that look like OpenSea support. They DM users who post complaints, offering to "help." They ask for seed phrases or to connect wallets to fake sites. Thousands of users have lost NFTs this way.
How to avoid: OpenSea support never DMs first. Never share seed phrase with anyone, ever.
4. Malicious Offer Scams
You receive an offer for your NFT that's higher than floor price, but in a worthless token instead of ETH/WETH. If you accept, you get worthless tokens and lose your NFT.
How to avoid: Only accept offers in ETH, WETH, or other legitimate currencies. Check the token contract if unsure.
5. Airdrop Drain NFTs
Free NFTs appear in your wallet's "Hidden" section. If you try to list, transfer, or interact with them, they execute a drain contract and steal your valuables.
How to avoid: Never interact with unexpected NFTs. Leave them hidden forever. Don't try to sell or burn them.
Scammers register fake domains:
✗ opensea.com (fake)
✗ opensae.io (fake)
✗ opensea.app (fake)
✗ opensea.org (fake)
✗ opensea-io.com (fake)
✓ opensea.io (REAL)
Type the URL directly. Bookmark it. Never click links from emails or DMs.
Safety Checklist:
- ✓ Bookmark opensea.io
- ✓ Never connect to unknown sites
- ✓ Use a burner wallet for new mints
- ✓ Verify collection before buying
- ✓ Don't click links in DMs
- ✓ Revoke permissions regularly
Random NFTs appearing in your wallet's "Hidden" section are almost always scam tokens. Don't try to sell or interact with them - just leave them hidden forever.
OpenSea vs Competitors in 2026
| Feature | OpenSea | Blur | Magic Eden |
|---|---|---|---|
| Marketplace Fee | 2.5% | 0.5% | 1.95% |
| Monthly Volume | $2.8B | $1.9B | $850M |
| User Interface | Beginner-friendly | Pro trader focus | Clean, modern |
| Chains Supported | 8+ networks | Ethereum mainly | 5+ networks |
| Listing Cost | Free (lazy mint) | Free | Free |
| Advanced Tools | OpenSea Pro | Portfolio bidding | Launchpad |
When to Use OpenSea vs Others
- Use OpenSea if: You're new to NFTs, want the largest selection, need multi-chain support, prefer simple interface
- Use Blur if: You're an active trader, want lowest fees, use floor sweeping, make many transactions
- Use Magic Eden if: You collect Solana NFTs, want lower fees than OpenSea, like their launchpad
OpenSea Pro: Advanced Features
Launched 2023 to compete with Blur. Available at pro.opensea.io for power users.
OpenSea Pro Features
- Aggregated listings: See listings from OpenSea, Blur, LooksRare all in one place
- Real-time data: Live floor prices, sales, and stats
- Portfolio tracking: See your NFT values across wallets
- Batch actions: Make offers on multiple NFTs at once
- Advanced analytics: Rarity rankings, holder distribution, wash trade detection
Understanding OpenSea Verification
Blue Checkmark
OpenSea verifies collections that meet criteria: established project, clear ownership, significant trading volume. Blue checkmark doesn't mean the NFT will have value, just that it's the authentic collection.
Verification Isn't Perfect
Some verified collections have still been scams or failed projects. Verification just confirms identity, not quality or legitimacy of the project's promises.
How to Verify Without Blue Check
- Go to project's official Twitter (verified account)
- Find their pinned OpenSea link or website
- Compare contract address on Etherscan
- Check collection has reasonable volume and holders
- Verify creation date matches project launch
Gas Optimization on OpenSea
Timing Your Transactions
Ethereum gas fees vary dramatically by time of day and day of week:
- Cheapest: Saturday/Sunday 2-6 AM UTC ($10-15 per transaction)
- Most expensive: Tuesday-Thursday 2-6 PM UTC ($40-80 per transaction)
- Moderate: Weekday mornings UTC ($15-30)
Use Polygon for Practice
OpenSea supports Polygon (Layer 2). Gas fees are $0.01-0.10 instead of $10-50. Perfect for:
- Learning how NFT purchases work
- Buying cheap NFTs to experiment
- Minting your own NFTs without cost
- Trading frequently without gas eating profits
Network Comparison
| Network | Avg Gas Fee | Transaction Speed | Best For |
|---|---|---|---|
| Ethereum | $10-50 | 12 seconds | Blue-chip NFTs |
| Polygon | $0.01-0.10 | 2 seconds | Practice, cheap NFTs |
| Solana | $0.01 | 400ms | Fast trading |
| Arbitrum | $0.50-2 | 1 second | Lower fees, ETH security |
Collection Analytics: What to Check
Key Metrics
- Floor price: Lowest listed price (but check if real or fake listings)
- Volume (7d/30d): Real trading activity shows demand
- Unique owners: Higher % = better distribution, less manipulation
- Listed %: If 30%+ listed, holders want to sell (red flag)
- Sales count: More sales = more liquidity (easier to sell later)
Red Flags
- Floor price dropping consistently for weeks
- Same wallets trading back and forth (wash trading)
- Huge supply listed (30%+ of collection)
- Very few unique holders (concentrated ownership)
- Team stopped updating social media
- Roadmap promises never delivered
Use advanced filters to find better deals:
- Set max price below floor to catch panic sellers
- Filter by traits to find rare pieces
- Sort by "Recently listed" for fresh inventory
- Check "Buy now" only to skip auction-only listings
- Use "Has offers" to see what others are bidding
OpenSea Mobile App
OpenSea has iOS and Android apps. Convenient but less secure than desktop with hardware wallet.
Mobile App Pros
- Browse collections anywhere
- Get notifications on offers and sales
- Quick price checks
- Easy to share NFTs
Mobile App Cons
- Easier to make mistakes on small screen
- Can't use hardware wallet for signing
- More vulnerable if phone is compromised
- Harder to verify contract addresses
Mobile Security Tips
- Use a separate wallet for mobile (not your vault)
- Only keep small amounts on mobile wallet
- Enable biometric security
- Never use public WiFi for transactions