How to List NFTs on OpenSea: The Complete 2026 Guide
Table of Contents
- Prerequisites: What You Need Before You Start
- Creating Your OpenSea Account
- Connecting MetaMask to OpenSea
- Importing Your Collection from a Smart Contract
- Setting Collection Details
- Listing Individual NFTs
- Setting Royalties with EIP-2981
- OpenSea Fees Explained
- Promoting Your Listings
- Tips for Visibility and Sales
You've deployed your smart contract. Your NFTs are minted and their metadata lives on IPFS. Now comes the part that actually matters for reaching collectors: listing on a marketplace. OpenSea remains the largest NFT marketplace in 2026, and if you're selling on Polygon (like we do with Quantum Genesis), listing is gas-free for sellers.
This guide walks through every step — from creating your account to optimizing listings for maximum visibility. I'll use our own collection (Quantum Genesis on Polygon) as a real-world example throughout.
1. Prerequisites: What You Need Before You Start
Before touching OpenSea, make sure you have these in place:
- A deployed ERC-721 or ERC-1155 contract — OpenSea auto-detects contracts on Ethereum, Polygon, Arbitrum, Optimism, Base, Avalanche, and other supported chains.
- Minted NFTs — Your tokens must exist on-chain. OpenSea reads directly from the blockchain.
- Metadata on IPFS or a reliable host — Each token's
tokenURImust resolve to valid JSON withname,description,image, and optionallyattributes. - MetaMask (or another supported wallet) — MetaMask is the most common. Install the browser extension.
- Some native gas tokens — On Polygon, you need a small amount of MATIC for approvals. On Ethereum, you need ETH.
For Quantum Genesis, our contract is 0x488fCfaEA5fDf1cF6BAED5e8A34D7858033E1a27 on Polygon, with all 100 NFTs minted and metadata pinned to Pinata IPFS.
2. Creating Your OpenSea Account
OpenSea doesn't have a traditional "sign up" flow. Your account is your wallet.
- Go to opensea.io.
- Click the wallet icon (top right) or "Login".
- Select MetaMask from the wallet options.
- MetaMask will pop up asking you to connect. Approve the connection.
- OpenSea may ask you to sign a message to verify ownership — this is a gasless signature, not a transaction.
Once connected, you have an account. Go to your profile settings to add a username, bio, profile picture, and banner. These details appear on your public profile and lend credibility to potential buyers.
Profile Optimization Tips
- Use a recognizable username — ideally matching your brand or project name.
- Write a concise bio mentioning your collection's unique angle.
- Add links to your website, Twitter/X, and any relevant social channels.
- Upload a high-quality profile image (at least 350x350 pixels).
3. Connecting MetaMask to OpenSea
If you deployed your contract from a specific wallet, you must connect that same wallet to OpenSea. The deployer address is automatically recognized as the collection owner, giving you access to collection-level settings.
Switching Networks in MetaMask
If your NFTs are on Polygon (like ours), make sure MetaMask is set to the Polygon network:
- Open MetaMask and click the network dropdown at the top.
- Select "Polygon Mainnet." If it's not listed, add it manually:
- Network Name:
Polygon Mainnet - RPC URL:
https://polygon-rpc.com - Chain ID:
137 - Symbol:
MATIC - Explorer:
https://polygonscan.com
- Network Name:
OpenSea supports multiple chains simultaneously — but your wallet must be on the correct network when you sign transactions like listings.
4. Importing Your Collection from a Smart Contract
This is where OpenSea shines: you don't need to manually import anything. OpenSea's indexer automatically detects ERC-721 and ERC-1155 contracts and creates a collection page.
After minting, your NFTs typically appear on OpenSea within minutes. If they don't show up immediately:
- Visit
https://opensea.io/assets/matic/YOUR_CONTRACT_ADDRESS/1(replace with your contract and token ID). - Click "Refresh metadata" on any NFT page to force OpenSea to re-index.
- For bulk refresh, use the OpenSea API endpoint:
POST /api/v2/chain/matic/contract/{address}/nfts/{id}/refresh.
5. Setting Collection Details
Once your collection is detected, go to your collection page and click "Edit collection" (only visible to the deployer wallet). Here you can set:
Essential Fields
- Collection name — This is pulled from your contract's
name()function, but you can customize it. - Description — Tell the story. For Quantum Genesis, we explain that each NFT was generated from real quantum computer measurements. This is your elevator pitch.
- Category — Choose "Art" or "Generative Art" for algorithmic/quantum art.
- Logo image — 350x350 pixels minimum. Use a representative piece from your collection.
- Banner image — 1400x350 pixels. Create a banner that showcases your collection's visual style.
- Featured image — 600x400 pixels. This appears in collection cards on the homepage.
Links and Social
- Website URL
- Discord server
- Twitter/X handle
- Medium or blog URL
Fill out every field you can. Collections with complete profiles get better visibility in search results and OpenSea's editorial picks.
6. Listing Individual NFTs
With your collection set up, it's time to list NFTs for sale. Navigate to any NFT in your collection and click "List for sale."
Fixed Price Listing
The simplest option. You set a price in ETH (or WETH/MATIC on Polygon) and buyers can purchase immediately.
- Click "List for sale" on the NFT page.
- Select "Fixed price."
- Enter your price. Research comparable collections to price competitively.
- Set the listing duration (1 day, 3 days, 7 days, 1 month, 3 months, or 6 months).
- Click "Complete listing" and sign the transaction in MetaMask.
On Polygon, listing is completely gas-free. You're signing a gasless order, not sending a transaction. Buyers pay the gas when purchasing.
Auction Listing
OpenSea supports English auctions (ascending price) and Dutch auctions (descending price).
- English auction — Set a starting price. Bidders compete upward. The highest bidder wins when the auction ends. Bids are made in WETH.
- Dutch auction — Set a starting price and ending price. The price decreases linearly over time. The first buyer to accept the current price gets the NFT.
For a new collection, I recommend starting with fixed-price listings. Auctions work better once you have an established audience and demand.
Batch Listing
If you have many NFTs to list (like our 100), doing it one by one is painful. Options:
- OpenSea UI — Select multiple NFTs from your collection page and list them in batch. You'll still need to sign once per NFT.
- OpenSea API — For developers, use the Listing API to create listings programmatically. You'll need an API key from the OpenSea developer portal.
- Custom script — Use the Seaport protocol SDK to create and sign orders programmatically. This is what we use for Quantum Genesis.
7. Setting Royalties with EIP-2981
Royalties ensure you earn a percentage of every secondary sale. There are two layers:
On-Chain Royalties (EIP-2981)
If your smart contract implements the ERC2981 interface, marketplaces query it to determine royalty amounts. Our Quantum Genesis contract sets 5% royalties at the contract level:
// In the Solidity contract constructor
_setDefaultRoyalty(owner, 500); // 500 basis points = 5%
This is the most reliable method because it's enforced by the contract itself. OpenSea reads the royaltyInfo() function and applies it automatically.
OpenSea Collection Royalties
You can also set royalties through OpenSea's collection settings. Go to Edit Collection and set the "Creator earnings" percentage plus a payout address. OpenSea enforces these on its own platform. Set this to match your on-chain royalties for consistency.
Important: As of 2025, OpenSea enforces creator fees on collections that use the Operator Filter Registry or have on-chain EIP-2981 royalties. Collections without on-chain enforcement may see optional creator fees (buyers can choose to pay 0%). Always implement EIP-2981 in your contract.
8. OpenSea Fees Explained
Understanding fees is critical for pricing:
| Fee Type | Amount | Who Pays |
|---|---|---|
| OpenSea service fee | 2.5% | Seller (deducted from sale price) |
| Creator royalties | 0-10% (you set this) | Seller (deducted from sale price) |
| Gas fees (listing) | Free on Polygon | N/A |
| Gas fees (purchase) | Variable | Buyer |
With our 5% royalty on Quantum Genesis, the total fee per sale is 7.5% (2.5% OpenSea + 5% creator). If an NFT sells for 1 ETH, the seller receives 0.925 ETH.
9. Promoting Your Listings
Listing is only half the battle. You need to drive traffic to your collection.
Social Media Strategy
- Twitter/X — The primary channel for NFT promotion. Share your collection's story, behind-the-scenes process, and individual pieces. Use relevant hashtags: #NFT #NFTArt #QuantumArt #GenerativeArt #PolygonNFT.
- Discord — Build a community around your project. Share updates, engage with collectors, and create exclusive channels for holders.
- Instagram — Visual platform perfect for art NFTs. Post high-quality images of your pieces.
- Reddit — Share in r/NFT, r/CryptoArt, r/generativeart, and niche communities.
Content Marketing
- Blog posts (like this one!) explaining your process
- Dev.to or Medium articles for technical audiences
- YouTube/TikTok videos showing the creation process
- Collaborations with other artists and collectors
OpenSea-Specific Promotion
- Keep your collection metadata complete and polished.
- Create "drops" for coordinated launches.
- Engage with the OpenSea community on their official Discord.
10. Tips for Visibility and Sales
After listing hundreds of NFTs across multiple projects, here are the tactics that actually move the needle:
Pricing Strategy
- Price a few pieces low to generate initial sales and floor activity. OpenSea's algorithm favors collections with trading volume.
- Tier your prices by rarity or attributes. Our quantum-processor-based tiers (Origin Quantum pieces vs. IBM Quantum pieces) create natural price differentiation.
- Don't overprice at launch. A collection with zero sales at 1 ETH each is less attractive than one with 10 sales at 0.01 ETH each.
Metadata Quality
- Rich attributes improve discoverability. OpenSea creates filters from your trait metadata. Collectors can search by attributes like "Quantum Processor: IBM ibm_fez" or "Color Palette: Nebula."
- High-resolution images load better and look more professional.
- Descriptive names are better than "NFT #47." (Though numbered series work fine for generative collections.)
Community Building
- Respond to every comment and offer on OpenSea.
- AMA sessions about your process build trust.
- Consider airdrops or giveaways to early supporters.
- Tell the story behind each piece — for us, each NFT has a quantum certificate showing exactly which processor and circuit generated it.
Timing
- List during peak activity hours (typically US evenings / European afternoons).
- Coordinate listing announcements with social media posts.
- Refresh listings periodically — stale listings drop in search rankings.
Cross-Promotion
- Feature your OpenSea collection in your email signature, blog, and social bios.
- Collaborate with other Polygon-based collections for cross-promotion.
- Submit your collection to NFT calendars and directories.
Final thought: OpenSea is a tool, not a strategy. The marketplace handles the infrastructure — discovery, transactions, provenance tracking. But driving demand is your job. The best-listed NFT in the world won't sell without an audience that cares about your work. Build the story first, then the listing.
Desenvolvo sistemas que usam hardware quântico real (IBM Quantum, Origin Quantum) para gerar arte e NFTs com proveniência verificável on-chain. Escrevo sobre computação quântica aplicada, criptografia, Web3 e arte generativa — tudo com código que roda em processadores quânticos de verdade.
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