## Working with Testnets We're going to learn how to work with Testnets. Working with Testnets is optional, but it's a great way to experiment with transactions and learn about gas without risking real money. **Testnet Basics** At the time of recording, Sepolia is a popular Testnet. You can find the most up-to-date information about Testnets on the GitHub repository associated with this course (Cyprin Foundry Full Course, formerly known as ChainAccelOrg Foundry Full Course). Testnets are constantly changing, so it's important to check the recommended Testnets section on the GitHub repository. We can use Sepolia Etherscan (`sepolia.etherscan.io`) to view our account balance and transactions on the Sepolia Testnet. *Important:* Getting testnet faucets can be challenging. If you are unable to get any testnet faucets, please do not waste a ton of time trying to get it, and just use tenderly virtual networks instead! **Sending a Testnet Transaction** To send a transaction on a Testnet, we need to use a **faucet**. A faucet allows us to get free Testnet tokens. * **Recommended Faucet:** `faucets.chain.link` (check the GitHub repository for the most up-to-date links). **Connecting Your Wallet to a Faucet** 1. Connect your MetaMask wallet to the faucet website. 2. Select the Sepolia Testnet in your MetaMask. 3. Request Test ETH (you can also request Test LINK in the future). 4. Log in via Twitter (or use another faucet if you don't have Twitter). **Receiving Testnet ETH** After requesting Test ETH, you'll see a transaction hash. This hash represents your transaction on the Sepolia Testnet. You can view the transaction details on Sepolia Etherscan. Once the transaction is complete, you'll see your Test ETH balance update in your MetaMask. **Understanding Transaction Details** You can view transaction details on Sepolia Etherscan. Important details include: * **Transaction hash:** A unique identifier for the transaction. * **Status:** Whether the transaction was successful. * **From:** The address that sent the transaction. * **To:** The address that received the transaction. * **Value:** The amount of ETH sent (in this case, 0.1 Test ETH). **Important Notes:** * Testnet transactions are not worth any real money. * Use Testnet transactions sparingly. * You can find information about different Testnets in the GitHub repository. * We'll cover adding different networks to your MetaMask in the future. **Congratulations on your first transaction!** Now, let's use this Testnet transaction to learn more about gas.