Note: the Kiln testnet was deprecated by the Ethereum Foundation during the week of September 12th, and as of September 26th, 2022, Alchemy's Kiln faucet has been deprecated.

Testnets allow developers to test the functionality of their applications before deploying them to a blockchain’s mainnet’s production environment. Before Ethereum switches its consensus mechanism from proof-of-work to proof-of-stake, developers must have a safe environment to test their applications and guarantee a smooth transition when the Ethereum 2.0 upgrade takes place. 

The Ethereum Kiln merge testnet helps developers test their applications on the post-merge Ethereum blockchain. The Kiln testnet launched as a proof-of-work blockchain in parallel with the Beacon chain, and merged on March 15, 2022, transitioning to a fully proof-of-stake system allowing developers, node operators, and stakers to get familiar with a post-merge Ethereum environment. 

This article covers the essential aspects of the Kiln testnet, including why a developer would use it, how to acquire and send testnet Ether, and an overview of helpful tools for building, monitoring, and testing applications.

What is the Kiln testnet?

The Kiln testnet simulates the Ethereum mainnet's merge with the beacon chain, initiating the complete transition from proof-of-work to proof-of-stake network consensus. Kiln’s merge testnet acts as a development environment for developers, node validators, and stakers to experiment with their application(s) functionality on the upcoming Ethereum upgrade to proof-of-stake consensus before The Merge takes place. 

Kiln launched as a proof-of-work system and transitioned to proof-of-stake on March 15, 2022, and is maintained by the Ethereum developer team. The public Kiln testnet currently has 110,000 active validators with 3.5 million ETH staked. The network has processed 1.3 million total transactions at an average of eight thousand per day since its inception.

Is the Kiln testnet deprecated?

As of September 26th, 2022, Alchemy's Kiln faucet has been deprecated and no longer serving active requests as the Kiln Testnet has been deprecated by the Ethereum Foundation.

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Why was a developer likely to use the Kiln merge testnet vs. other testnets?

When choosing a testnet, a developer would deploy to the Kiln testnet to experiment with their application's functionality on a proof-of-stake beacon chain. 

For instance, if a developer created an NFT smart contract and wanted to ensure it ran as intended after the Ethereum merge, they could use the Kiln testnet to test the contract functionality. 

There are many different types of testnets, and each serves a different purpose for testing applications. For an overview, read Alchemy’s guide on Ethereum testnets to learn when different testnets should be utilized. 

Many of the current testnets are still using the proof-of-work consensus and will soon be deprecated and replaced with proof-of-stake testnets. 

How to Connect to Kiln testnet with Metamask

All developers, stakers, and node operators should use the Kiln merge testnet to ensure their setups will work properly post-merge. Here is how you can connect your Metamask wallet to the Kiln testnet and test your dApps. 

Many Ethereum wallets exist, but we will use Metamask, a browser-based wallet, for this tutorial.

Method 1: Adding Kiln testnet automatically

1. Go to Ethereum's Kiln testnet page 
2. Click “Add network to Metamask”

3. Approve the transaction in Metamask
4. Click “Switch network”

Your Metamask should now be connected to Kiln!

Method 2: Add the Kiln Testnet Manually

1. In the top right corner of your Metamask wallet, click on the profile image and select “settings”

2. Click on “Networks” and select “Add Network”.

3. Enter the parameters below to add the Kiln testnet to your Metamask

• Network Name: Kiln
• Network URL: https://rpc.kiln.themerge.dev/
• Chain ID: 1337802
• Symbol: ETH
• Block Explorer (optional): https://explorer.kiln.themerge.dev/ 

How to Get Kiln testnet ETH

As of September 26th, 2022, Alchemy's Kiln faucet has been deprecated and is no longer serving active requests because the Kiln testnet was deprecated by the Ethereum Foundation during the week of September 12th, 2022. For historic purposes, here is how developers were able to request Kiln ETH from Alchemy's testnet before it was deprecated.

To test applications on the Kiln testnet, you will need to get Kiln ETH. Kiln's testnet Ether has no real value and can be acquired from a Faucet, which is a web application that allows users to request testnet ETH and send it to a specific address. 

Here is how you can request testnet ETH from Alchemy's Kiln faucet.

1. Click on your Metamask wallet address to copy it to the clipboard.

2.  Log in or sign up for a free Alchemy account to get 5X Kiln Ethereum for free.
3. On Alchemy’s Kiln faucet, paste your Metamask address in the “send me ETH” input field. 

Your Metamask should now have some Kiln testnet ETH. 

If you don't see any ETH after 13-15 seconds, click on the transaction address to see the transaction and network verification details on the Kiln block explorer.

If the transaction is verified, ensure your Metamask network is still set to Kiln.

How to Send Kiln Testnet ETH

Here is how to send Kiln testnet ETH.

1. Copy an address to which you’d like to send the Kiln ETH.

2. Click “send” on Metamask.

3. Paste the address copied in step 1 and enter the amount of ETH to send.

Metamask will show the gas fee required to verify the transaction and the total cost. 

Since Kiln is a testnet and Proof-of-Stake, the gas fee should be low.

4. Click “confirm” to send Kiln ETH

Wait for the transaction to process. If the network is not busy, the transaction will be added to the next block and verified within approximately 13-15 seconds.

How to Confirm the Kiln ETH was Sent Successfully

1. Click on the pending transaction under the activity tab 
2. Navigate to the transaction status and click “View on block explorer”

Once the Kiln testnet transaction is complete, the status will change from “pending” to “confirmed.”

The Kiln ETH should now appear in the wallet that it was sent to.

What are the best Kiln testnet tools?

Here is a list of helpful tools, APIs, and libraries a developer will need to build, monitor, and test an application on the Kiln testnet.

• Alchemy Account - get 5X free Kiln ETH and deploy apps on Ethereum testnets
• Kiln Docs - learn how to test applications on the Kiln testnet
• Kiln Website - learn more about the Kiln testnet
• Kiln Block Explorer - explore transactions and smart contracts on the Kiln testnet
• Alchemy’s Composer tool - compose JSON-RPC calls to test on the Kiln testnet
• Kiln faucet - get free Kiln ETH and get 5 times more fake ETH with an Alchemy account
• Staking on Kiln - participate in staking on the Kiln testnet
• Running a node on Kiln - learn how to run a Kiln testnet node
• Alchemy web3 library - learn more about alchemy-web3.js
• Beacon Chain Explorer - get live updates on active validators, staked ETH, and blocks