Goerli is a proof of authority (PoA) testnet web3 developers use to test blockchain applications before launching them on the Ethereum Mainnet. To test smart contracts on the Goerli testnet, developers need Goerli ETH to execute transactions. Dapp developers can get testnet ETH for free using a Goerli Faucet.

What is the Goerli testnet?

Goerli is a testnet, a decentralized computing network who’s ledger is separate from the main Ethereum ledger, so transactions do not cross over between the two. It runs on a different consensus system, proof of authority, rather than the Ethereum mainnet proof of stake (PoS).

Goerli is one of Ethereum's most popular testnets and is used by web3 application developers to test their applications before launching them on the Ethereum Mainnet.

What is the difference between Proof of Stake and Proof of Authority?

In the proof of stake model, the longest chain is the chain that all participants in the network agree to be true. Validators are the participants that add new blocks of transactions to this chain.

Under the proof of stake model, validators are randomly chosen from a pool of actors willing to offer 32 ETH as collateral to be taken away in cases of malicious behavior. 

The logic behind this consensus model is that the collateral discourages validators from acting maliciously because they would lose a non-trivial amount of Ethereum and/or lower the price of Ethereum and their own net worth.

The proof of authority model differs from the proof of stake model in forcing its validators to reveal their real-world identities. Once a majority of the validators agree that a new block of transactions is legitimate, it is signed off and added to the longest chain. 

Because it would be expensive to verify the identities of a large number of players, only small private chains such as the Goerli testnet have adopted proof of authority. 

Why do developers build on the Goerli testnet?

Developers build their dApps on the Goerli testnet over other testnets because Goerli supports a wider variety of node software (e.g. Geth, Parity, Nethermind, Hyperledger) than alternatives like Rinkeby and Kovan which only support Geth and Parity respectively.

As a separate ledger from the main Ethereum network, whatever happens on the Goerli testnet stays on Goerli. Decentralized application developers choose to use the Goerli testnet because it is a safe space to test their decentralized applications for security risks and bugs before releasing them on the Ethereum mainnet.

What is Goerli ETH?

Goerli ETH is fake testnet ETH exclusive to the Goerli testnet that you use exclusively to pay for computation.

Developers can get Goerli ETH to begin running dApps at this Goerli  faucet page on the Alchemy site.  

Developers building Ethereum applications can get Goerli ETH for free using a Goerli Faucet.

How do developers use test ETH on the Goerli testnet?

Developers use test ETH funds to pay for transactions on the Goerli testnet, but  don’t worry, Goerli ETH is free.

Thanks to the limited amount of Goerli testnet ETH given to each wallet daily from this Ethereum faucet and every transaction requiring Goerli ETH,  the system prevents malignant actors from overloading the testnet with transactions.

What are Goerli faucets?

The Goerli Ethereum faucet is where developers can acquire Goerli testnet ETH for free.

Most Goerli faucets will require you to authenticate yourself on Twitter or confirm you are a real human before placing you in a queue to get for a Goerli testnet tokens.

Alchemy’s Goerli test network faucet is free, fast, and does not require authentication. However, if you sign up for a free Alchemy account where you can build and test applications on the Goerli testnet, you can get 0.05 ETH per day.

How to Get Testnet ETH from a Goerli Faucet

1. Register for a free Alchemy account or sign in if you already building on Alchemy.

2. Go to goerlifaucet.com

After clicking ‘Send Me ETH’, a pop up screen will congratulate you on successfully requesting Goerli ETH from the Goerli testnet faucet.

3. Copy and paste your wallet address or ENS domain

Upon exiting the popup, a transaction hash should now be visible in the ‘Your Transactions’ table. Click on the transaction hash to view the details of what happened, like how much Goerli faucet ETH you received from the goerli-faucet and what the gas price of the transaction was.

If you wish to browse all transactions on the Goerli network, you can do so on this Goerli testnet explorer.

4. Click Send Me ETH

With Goerli ETH funds in your wallet, you can now connect to the Goerli testnet and start using your ETH to test your smart contracts!