Testnets are designed to mimic the environment of mainnet to enable developers to test and troubleshoot applications without any value being at risk before mainnet deployment. 

It’s generally considered good practice to test any contract code on a testnet before deploying it on mainnet—most onchain applications have copies deployed to testnets to enable developers to troubleshoot.

In this guide, we’ll show you how to get testnet ETH tokens on the Sepolia network to test your Chainlinked smart contract before deploying it on mainnet.

What Is the Sepolia Testnet?

Sepolia is the recommended default testnet by Ethereum core developers for smart contract application development. Sepolia was initially launched as a proof-of-authority testnet in October 2021 by Ethereum core developers. The network later transitioned to a proof-of-stake consensus mechanism to mimic the operating environment of Ethereum mainnet.

Sepolia uses a permissioned validator set. Since it’s a relatively new test network with a small state, the network is quick to sync to, and running a node on it requires less storage than on mainnet or other testnets. These features are useful for developers who quickly want to interact with the network directly and run a node.

Compared to other Ethereum testnets, such as Goerli, Sepolia’s total supply of testnet ETH tokens is uncapped, making it more likely that developers using Sepolia will continue to be able to access testnet tokens in the future.

How To Get Sepolia Testnet ETH

Using the Chainlink Testnet Faucet, you can request testnet ETH tokens to test your Chainlinked smart contract on Sepolia.

1. Go to https://faucets.chain.link/sepolia.
2. Make sure you have selected the Ethereum Sepolia network since this is where you want to receive the testnet ETH.
3. Click “Connect wallet” so the faucet app can detect the selected network and your wallet address.
4. If you want to receive testnet funds at a different address than the one you connected, paste the address in the “Wallet address” section. This field defaults to your connected wallet address otherwise.
5. Select whether you’d like to receive Sepolia testnet ETH and/or Sepolia testnet LINK.
6. Verify you’re human by clicking on “Login via GitHub” and connecting your valid GitHub account. This step is necessary to protect against spam requests.
7. Click on “Send request”. The tokens are then transferred from the faucet to the wallet address that you specified.

If you’d like to learn more about testing your Chainlinked smart contract, visit the Chainlink Dev Hub.

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