How to deploy NFT smart contract on Polygon testnet for free

NFT
1

I’m working on an NFT project and want to test my smart contract without spending real money on gas fees. I found a guide that uses Ethereum mainnet but it requires actual payments for deployment and testing.

Here’s my current Hardhat configuration:

require('dotenv').config();
require("@nomiclabs/hardhat-ethers");

const { API_KEY, WALLET_PRIVATE_KEY } = process.env;

module.exports = {
  solidity: "0.8.4",
  defaultNetwork: "goerli",
  networks: {
    localhost: {},
    goerli: {
      url: `https://eth-goerli.g.alchemy.com/v2/${API_KEY}`,
      accounts: [`0x${WALLET_PRIVATE_KEY}`]
    },
    mainnet: {
      chainId: 1,
      url: `https://eth-mainnet.g.alchemy.com/v2/${API_KEY}`,
      accounts: [`0x${WALLET_PRIVATE_KEY}`]
    }
  }
}

I heard that Polygon offers free testing environments. Can someone guide me on how to modify this setup to use Polygon’s testnet instead? What network configuration should I add to test my NFT contract without any costs?

2

Switched from Goerli to Polygon Mumbai last year - best decision ever. Way faster deployments than Ethereum testnets. Your Hardhat setup barely needs tweaking - just add Mumbai config with RPC URL https://rpc-mumbai.matic.today/ and chainId 80001. Pro tip: always verify contracts on Polygonscan Mumbai after deploying with hardhat-etherscan plugin. Saves tons of debugging headaches later. Grab test MATIC from multiple faucets since they’ve got daily limits. I keep both the official Polygon faucet and Alchemy’s bookmarked as backups. Gas costs are basically free, even for complex NFT contracts with metadata and royalties.

3

polygon mumbai is the way to go for free testing! just add this to your networks config: mumbai: { url: "https://polygon-mumbai.g.alchemy.com/v2/${API_KEY}", accounts: [\0x${WALLET_PRIVATE_KEY}`], chainId: 80001 }then grab free matic from polygon faucet and deploy withnpx hardhat run scripts/deploy.js --network mumbai`. works great for nft testing

4

Nice! Polygon testnet is perfect for free testing - I’ve used it for months without spending anything on gas :smile:

What kind of NFT project are you building? Art pieces or something utility-based?

For hardhat config, add polygon mumbai testnet. Use https://rpc-mumbai.maticvigil.com/ or Alchemy’s polygon endpoints. Chain ID is 80001.

Have you written your NFT contract yet? Using OpenZeppelin’s ERC721 or something custom? Sometimes contracts need tweaks when switching networks.

You’ll need test MATIC for deployment - even though it’s free, your wallet needs the tokens. There are faucets for free test tokens. Found those yet?

What’s your biggest challenge so far? The smart contract or frontend integration?