Network
Launch Date
Consensus
Note
Sepolia
Oct 2021
PoW
Like-for-like representation of Ethereum
Görli
Jan 2019
PoA
Proof-of-Authority
Kiln
Mar 2022
PoS
Post-Merge (for ETH2), shadow fork of the mainnet
Kintsugi
Dec 2021
PoS
DEPRECATED, use Kiln; post-Merge (for ETH2)
Ropsten
Nov 2016
PoW
DEPRECATED, use Sepolia; the Merge to happen on Jun 8, 2022
Rinkeby
Apr 2017
PoA
DEPRECATED, use Görli and Görli Faucet
Kovan
Mar 2017
PoA
DEPRECATED, use Sepolia or Görli
List of active and deprecated Ethereum testnets, including Kintsugi.
Features
Optimistic rollup 
ZK-rollup 
Proof
Uses fraud proofs to prove transaction validity. 
Uses validity (zero-knowledge) proofs to prove transaction validity. 
Capital efficiency
Requires waiting through a 1-week delay (dispute period) before withdrawing funds. 
Users can withdraw funds immediately because validity proofs provide incontrovertible evidence of the authenticity of off-chain transactions. 
Data compression
Publishes full transaction data as calldata to Ethereum Mainnet, which increases rollup costs. 
Doesn't need to publish transaction data on Ethereum because ZK-SNARKs and ZK-STARKs already guarantee the accuracy of the rollup state. 
EVM compatibility
Uses a simulation of the Ethereum Virtual Machine (EVM), which allows it to run arbitrary logic and support smart contracts. 
Doesn't widely support EVM computation, although a few EVM-compatible ZK-rollups have appeared. 
Rollup costs
Reduces costs since it publishes minimal data on Ethereum and doesn't have to post proofs for transactions, except in special circumstances. 
Faces higher overhead from costs involved in generating and verifying proofs for every transaction block. ZK proofs require specialized, expensive hardware to create and have high on-chain verification costs. 
Trust assumptions
Doesn't require a trusted setup. 
Requires a trusted setup to work. 
Liveness requirements
Verifiers are needed to keep tabs on the actual rollup state and the one referenced in the state root to detect fraud. 
Users don't need someone to watch the L2 chain to detect fraud. 
Security properties 
Relies on cryptoeconomic incentives to assure users of rollup security. 
Relies on cryptographic guarantees for security. 
Start building
on Alchemy.
Sign up for free
Start building on Optimism.
Sign up for free
Start building on Arbitrum.
Sign up for free
Start building on Ethereum.
Sign up for free
Start building on Polygon.
Sign up for free
Start building on Starknet.
Sign up for free
Start building on Flow.
Sign up for free
kiln faucet
Get free Kiln ETH.
Start building today
Goerli faucet
Get free Goerli ETH.
Start building today
mumbai faucet
Get free Mumbai Matic.
Start building today
rinkeby faucet
Get free Rinkeby
ETH.
Start building today
Start building on Ethereum.
Get started for free
Start building on Ethereum.
Get started for free
Start building on Flow.
Get started for free
Start building on Polygon.
Get started for free
Start building on Starknet.
Get started for free
Start building on Optimism.
Get started for free
Start building on Solana.
Get started for free
Start building on Solana.
Sign up for beta access
Start building on Solana.
Join the waitlist
Arbitrum logo
Start building on Arbitrum.
Get started for free
Testnets
TESTNETS OVERVIEW

What are Ethereum Testnets?

Purpose and How to Access
Last Updated:
April 19, 2022

Introduction

As more funds and users are onboarded to Web3 and decentralized finance (DeFi) services, security and reliability are becoming increasingly important for developers. Testnets are used by developers to ensure that the smart contracts and dApps (Decentralized Applications) they deploy are functional and secure. 

Developers can work with the same clients as they would on the mainnet but testnets operate on a separate ledger. This separation creates a low-risk environment where developers can test and experiment without the costs of deploying on the mainnet. 

Let's look deeper into what are testnets, the benefits of using a testnet, and how developers can access them.

What are testnets?

Testnets are test blockchain networks that act and perform similarly to the main networks (mainnets) they are associated with. Since they operate on separate ledgers from the mainnet, the coins on a testnet have no connection to transactions and value on the mainnet. This allows developers to deploy, test, and execute their projects on a functioning blockchain freely.

The cost of failure or mistakes on a mainnet is very high and at times irreversible so developers need an environment where they can comfortably work without these risks. 

Security is a high priority for developers working on any decentralized platform. Operating on a testnet also offers the benefit of both investigating any vulnerabilities in the platform as well as educating developers on how the platform works. For testnets that are for pre-network upgrades, it is important to investigate how newly developed changes function before they are merged with the mainnet.

Differences between mainnets and testnets

Most testnets have separate wallet systems to make it easier to manage coins and transactions outside of the mainnet. When deploying contracts and using services like Alchemy, testnets have distinct Network IDs .

For example, on the Ethereum network, the mainnet and testnets have the following IDs: 

1 - Ethereum mainnet 

3 - Ropsten testnet

4 - Rinkeby testnet

5 - Goerli testnet 

42 - Kovan testnet 

These IDs are used to ensure that the contract is deployed to the correct network and that the correct wallet system is used. Testnets do not experience the same amount of transaction frequency compared to their mainnets. Code is also not published publicly on testnets due to their changing nature compared to mainnets. 

Ethereum testnets

Ropsten 

The Ropsten testnet was launched in November 2016 and supports both Geth and Parity Ethereum node software. At the time of writing, it is the testnet that resembles the Ethereum network the most because it shares the same Proof-of-Work (PoW) consensus model

This allows developers to use a highly authentic testnet to work on but also opens the network to attacks that would be very expensive to perform on the Ethereum mainnet. One of these happened in February 2017 when attackers deployed a high volume of complex transactions on the network to bring it down. The network was later brought back up and safeguards were put in place to prevent similar attacks. 

Developers can view Ropsten transactions on Etherscan and can use faucets to add funds to a testnet wallet. 

Kovan

After the attack on the Ropsten network, there was a need for alternative testnets. Kovan launched in March 2017 to fulfill this need. The main difference between Ropsten and Kovan is their consensus models. 

Kovan uses a Proof-of-Authority (PoA)  model in which only specific nodes are authorized to confirm transactions and add any new blocks. Since the Parity team created this testnet, developers can only access it using the Parity node software. 

With Kovan,Developers can also view transactions on Etherscan and use faucets to add test coins.  

Rinkeby

Following the launch of Kovan, the Rinkeby testnet was launched in 2017 by the Ethereum team. Like Kovan, this testnet uses a modified PoA consensus model to confirm transactions. Unlike Kovan, the network only supports the Geth software and not Parity. 

To get testnet tokens for this network, you can use Alchemy's free Rinkeby Faucet and view transactions on Rinkeby Etherscan.

Here is a tutorial video on how to add funds to your wallet.

Source

Goerli 

Goerli is a testnet that combines both a PoA consensus mechanism with wider support of node software compared to Rinkeby and Kovan. Goerli supports both Geth and Parity as well as Nethermind and Hyperledger.

With this higher level of support, the popularity of Goerli has been increasing. It is also the first testnet that was attempted to be moved to the proof-of-stake mechanism before running into issues after multiple attempts.

Transactions can be viewed on Etherscan and Alchemy also offers a Goerli faucet

Morden / Kiln - the past and the future 

Morden was the very first Ethereum testnet. Ethereum shut it down in November 2016, because the network experienced several attacks and became highly congested with useless data that affected performance.

The Kiln testnet is the last planned testnet before other Ethererum testnets and mainnet move to a Proof-of-Stake consensus mechanism.  

Ethereum created this testnet to allow any node operators and developers to test before the company upgraded their other public Ethereum testnets.

At the time of writing, there is no official date on when this upgrade will occur. 

To start building on the Kiln testnet, get your Kiln ETH from Alchemy's free Kiln faucet.

Source

Conclusion

Utilizing testnets is a critical step in developing applications on any blockchain network, and to ensure the growth of Web 3, developers and users need to feel confident in the smart contracts and applications they use.

Testnets are key blockchain developer tools for creating the security and stability that users will increasingly demand as the growth of Web 3 applications continues. 

Want to start building decentralized applications on Ethereum testnets? Create a free Alchemy developer account to start building!

TESTNETS OVERVIEW

What are Ethereum Testnets?

Purpose and How to Access

Introduction

As more funds and users are onboarded to Web3 and decentralized finance (DeFi) services, security and reliability are becoming increasingly important for developers. Testnets are used by developers to ensure that the smart contracts and dApps (Decentralized Applications) they deploy are functional and secure. 

Developers can work with the same clients as they would on the mainnet but testnets operate on a separate ledger. This separation creates a low-risk environment where developers can test and experiment without the costs of deploying on the mainnet. 

Let's look deeper into what are testnets, the benefits of using a testnet, and how developers can access them.

What are testnets?

Testnets are test blockchain networks that act and perform similarly to the main networks (mainnets) they are associated with. Since they operate on separate ledgers from the mainnet, the coins on a testnet have no connection to transactions and value on the mainnet. This allows developers to deploy, test, and execute their projects on a functioning blockchain freely.

The cost of failure or mistakes on a mainnet is very high and at times irreversible so developers need an environment where they can comfortably work without these risks. 

Security is a high priority for developers working on any decentralized platform. Operating on a testnet also offers the benefit of both investigating any vulnerabilities in the platform as well as educating developers on how the platform works. For testnets that are for pre-network upgrades, it is important to investigate how newly developed changes function before they are merged with the mainnet.

Differences between mainnets and testnets

Most testnets have separate wallet systems to make it easier to manage coins and transactions outside of the mainnet. When deploying contracts and using services like Alchemy, testnets have distinct Network IDs .

For example, on the Ethereum network, the mainnet and testnets have the following IDs: 

1 - Ethereum mainnet 

3 - Ropsten testnet

4 - Rinkeby testnet

5 - Goerli testnet 

42 - Kovan testnet 

These IDs are used to ensure that the contract is deployed to the correct network and that the correct wallet system is used. Testnets do not experience the same amount of transaction frequency compared to their mainnets. Code is also not published publicly on testnets due to their changing nature compared to mainnets. 

Ethereum testnets

Ropsten 

The Ropsten testnet was launched in November 2016 and supports both Geth and Parity Ethereum node software. At the time of writing, it is the testnet that resembles the Ethereum network the most because it shares the same Proof-of-Work (PoW) consensus model

This allows developers to use a highly authentic testnet to work on but also opens the network to attacks that would be very expensive to perform on the Ethereum mainnet. One of these happened in February 2017 when attackers deployed a high volume of complex transactions on the network to bring it down. The network was later brought back up and safeguards were put in place to prevent similar attacks. 

Developers can view Ropsten transactions on Etherscan and can use faucets to add funds to a testnet wallet. 

Kovan

After the attack on the Ropsten network, there was a need for alternative testnets. Kovan launched in March 2017 to fulfill this need. The main difference between Ropsten and Kovan is their consensus models. 

Kovan uses a Proof-of-Authority (PoA)  model in which only specific nodes are authorized to confirm transactions and add any new blocks. Since the Parity team created this testnet, developers can only access it using the Parity node software. 

With Kovan,Developers can also view transactions on Etherscan and use faucets to add test coins.  

Rinkeby

Following the launch of Kovan, the Rinkeby testnet was launched in 2017 by the Ethereum team. Like Kovan, this testnet uses a modified PoA consensus model to confirm transactions. Unlike Kovan, the network only supports the Geth software and not Parity. 

To get testnet tokens for this network, you can use Alchemy's free Rinkeby Faucet and view transactions on Rinkeby Etherscan.

Here is a tutorial video on how to add funds to your wallet.

Source

Goerli 

Goerli is a testnet that combines both a PoA consensus mechanism with wider support of node software compared to Rinkeby and Kovan. Goerli supports both Geth and Parity as well as Nethermind and Hyperledger.

With this higher level of support, the popularity of Goerli has been increasing. It is also the first testnet that was attempted to be moved to the proof-of-stake mechanism before running into issues after multiple attempts.

Transactions can be viewed on Etherscan and Alchemy also offers a Goerli faucet

Morden / Kiln - the past and the future 

Morden was the very first Ethereum testnet. Ethereum shut it down in November 2016, because the network experienced several attacks and became highly congested with useless data that affected performance.

The Kiln testnet is the last planned testnet before other Ethererum testnets and mainnet move to a Proof-of-Stake consensus mechanism.  

Ethereum created this testnet to allow any node operators and developers to test before the company upgraded their other public Ethereum testnets.

At the time of writing, there is no official date on when this upgrade will occur. 

To start building on the Kiln testnet, get your Kiln ETH from Alchemy's free Kiln faucet.

Source

Conclusion

Utilizing testnets is a critical step in developing applications on any blockchain network, and to ensure the growth of Web 3, developers and users need to feel confident in the smart contracts and applications they use.

Testnets are key blockchain developer tools for creating the security and stability that users will increasingly demand as the growth of Web 3 applications continues. 

Want to start building decentralized applications on Ethereum testnets? Create a free Alchemy developer account to start building!

ALCHEMY SUPERNODE - ETHEREUM NODE API

Scale to any size, without any errors

Alchemy Supernode finally makes it possible to scale blockchain applications without all the headaches. Plus, our legendary support will guide you every step of the way.

Get started for free
Supernode footer
ALCHEMY SUPERNODE - ETHEREUM NODE API

Scale to any size, without any errors

Alchemy Supernode finally makes it possible to scale blockchain applications without all the headaches. Plus, our legendary support will guide you every step of the way.

Get started for free
Supernode footer