What is a testnet? A testnet faucet provides web3 developers with free tokens for deploying, testing, and optimizing smart contracts on test blockchains such as Sepolia, Goerli, and Mumbai. Because smart contracts on public, mainnet blockchains like Ethereum and Polygon require gas fees to run smart contracts, testnets provide blockchain developers with a network that mirrors production blockchain environments without requiring gas fees that cost real money. Get Testnet Tokens! transaction not found waiting for it to appear in the mempool bsc testnet usdt3 test token price freecodecamp api testing goerli eth value kroma sepolia explorer eth smart contracts testnet ftm address