How to Publish an NFT on OpenSea: Step-by-Step Guide

📁 Prerequisites

Item	Description
MetaMask Wallet	A crypto wallet to create and sign your NFT
ETH or MATIC	Needed to pay gas fees (ETH for Ethereum; MATIC for Polygon — which is often free to mint)
NFT Content	Your digital asset (image, video, audio, 3D, etc.)

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🛠️ How to Publish an NFT (on OpenSea)

✅ Step 1: Set up MetaMask Wallet

1. Go to https://metamask.io and install the browser extension.

2. Create a new wallet and save your recovery phrase securely.

3. Add some ETH to your wallet (buy or transfer from an exchange like Coinbase or Binance).

⚠️ For Polygon (cheaper), you’ll need MATIC tokens and to switch your network in MetaMask.

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✅ Step 2: Connect MetaMask to OpenSea

1. Visit https://studio.opensea.io

2. Click Profile (top right) → Choose MetaMask

3. Approve connection in MetaMask — your OpenSea account is now tied to your wallet

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✅ Step 3: Create a Collection (Optional)

• Go to your profile → My Collections

• Click Create a Collection

• Add:

  • Logo

  • Description

  • Royalties (% you’ll earn on resales)

  • Blockchain (Ethereum or Polygon)

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✅ Step 4: Mint (Publish) Your NFT

1. Click Create (top menu)

2. Upload your file (image, video, audio, or 3D model)

3. Fill in:

   • Name

   • Description

   • External link (optional)

   • Properties, levels, unlockable content (optional)

   • Blockchain: Ethereum or Polygon

4. Click Create — your NFT is now minted!

✅ On Polygon, this is free. On Ethereum, you may need to pay a one-time "initialize account" fee if it’s your first time.

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✅ Step 5: List Your NFT for Sale

1. Go to your newly minted NFT page

2. Click Sell

3. Set:

   • Price (fixed or timed auction)

   • Duration (e.g., 7 days)

4. Click Complete Listing

5. MetaMask will pop up → sign (and possibly pay gas fee if on Ethereum)

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🎉 Done! Your NFT is Now Live on OpenSea

• Share your NFT link on social media, Discord, or marketplaces

• Buyers can now purchase it directly from OpenSea

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🧠 Tips

Tip	Why It Matters
Use Polygon for low fees	No gas fees to mint or list NFTs
Add royalties	You’ll earn % on every resale
Include unlockable content	Useful for private files, perks, etc.
Verify NFT visibility	May take a few minutes to appear

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✅ Gasless Minting on Polygon (via Rarible or Mintable)

🧭 Why Polygon?

• No gas fees (for minting, listing, or transferring)

• Fast and low-cost transactions

• Fully supported on OpenSea and Rarible

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🔧 Option 1: Rarible on Polygon (Lazy Minting)

How to Mint:

1. Go to Rarible.com

2. Connect your wallet (e.g. MetaMask)

3. Switch network to Polygon (you can use Rarible’s prompt)

4. Click "Create"

5. Choose Polygon as the blockchain

6. Upload your file, add title/description

7. Enable "Free minting" — this is Rarible’s version of lazy minting on Polygon

8. Sign (gas-free) — your NFT will be visible on your Rarible profile

After Minting:

• Your NFT is lazy minted, but still appears on-chain via Polygon metadata

• You can list it on Rarible immediately

• It will appear on OpenSea automatically after a short delay (indexed by wallet)

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🔧 Option 2: Mintable (Gasless Store)

How to Mint:

1. Visit mintable.app

2. Create a "gasless store item"

3. Upload your art and metadata

4. Choose Gasless (Mintable Store) option — no crypto or gas needed

Notes:

• NFTs minted via Mintable’s gasless store are minted off-chain until purchased (like lazy minting)

• Once sold/minted, they can be transferred to OpenSea, but won’t show immediately unless manually imported

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🌐 OpenSea on Polygon

• OpenSea natively supports Polygon

• Go to OpenSea, connect the same wallet

• Switch network to Polygon

• Your Rarible Polygon NFTs will show under “Collected”

• You can list them for resale on OpenSea, zero gas

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💡 Tips

• Rarible lets you set royalties and collection metadata

• You only pay gas if you mint on Ethereum — Polygon is gas-free for mint + list

• No bridging required if you mint directly on Polygon