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
Learn
Solidity at
Alchemy
University
Get started today
curl 
https://release.solana.com/v1.10.32/solana-install-init-x86_64-pc-windows-msvc.exe 
--output 
C:\solana-install-tmp\solana-install-init.exe 
--create-dirs
Layer 2
BEDROCK TESTNET UPGRADE

Optimism Bedrock Testnet Migration Guide (2023)

Learn What the Optimism Bedrock Upgrade is & How to Prepare
Last Updated:
January 12, 2023
Table of Contents
Table of Contents
Table of Contents

{{building-on-optimism}}

Optimism is a layer 2 blockchain that uses optimistic rollups to help Ethereum scale. Optimism is undergoing a network upgrade to Optimism Bedrock, which introduces a series of performance improvements from its existing rollup architecture design. 

This article explains Optimism Bedrock, how it works, and what developers can expect when Optimism upgrades their Goerli testnet on Thursday, January 12th at approximately 10 AM PT, and when the mainnet is planned for upgrade in the weeks to follow.

What is Optimism Bedrock?

Optimism Bedrock is a network-wide upgrade for Optimism nodes that is designed to be the cheapest, fastest, and most advanced rollup architecture available, with support for multiple fault-proof and client implementations.

What improvements does Optimism Bedrock offer?

Optimism Bedrock is expected to bring a number of improvements to the Optimism mainnet. Some of the main changes and improvements that have been mentioned include:

1. Faster Deposit Transactions

Optimism Bedrock will significantly reduce the time required for deposit transactions to 2.5 minutes due to a smaller confirmation depth of 10-12 L1 blocks. This reduces the currently estimated deposit time which is roughly 10 minutes.

2. Lower Gas Fees

Optimism Bedrock introduces new changes to lower gas fees. Optimism Bedrock’s projected transaction fee reduction (20%) is a result of calldata compression and sending transactions to Ethereum using a “non-contract address,.” Besides lowering gas fees, Optimism will also mirror Ethereum’s gas fee design by Supporting EIP-1559.

3. More Predictable Block Production

Optimism Bedrock is expected to produce blocks every two seconds, compared to the current block production rate of 1 block per transaction, the same way Ethereum uses fixed block times.

4. Ethereum Equivalence

Ethereum Equivalence means Optimism Bedrock is designed to be the most seamless rollup possible by dovetailing all of Ethereum's “code, infrastructure, and design patterns,” into the design of Bedrock.

For example, some Ethereum Equivalents in Bedrock include:

What is the Optimism Bedrock migration timeline?

The Optimism Bedrock upgrade involves several steps:

  1. First, deposits and withdrawals will be paused on the legacy network
  2. The legacy sequencer will start rejecting transactions
  3. Then, the smart contracts on L1 will be upgraded and an irregular state transition will be performed on L2
  4. Next, the Bedrock sequencer will be started up.
  5. Finally, deposits and withdrawals will be re-enabled.

The upgrade is expected to result in significantly reduced transaction fees, faster node synchronization, and improved block production. It is not expected to affect everyday users of Optimism, but a mainnet upgrade proposal will be submitted to the Token House for approval after a successful testnet migration.

During both the testnet and mainnet upgrades there will be some downtime from infrastructure providers to upgrade nodes, however transaction history will be maintained.

How should Optimism dapp developers prepare for the Bedrock migration?

During a network-wide migration, developers should:

1. Plan for Downtime

Deposits, withdrawals, and transactions in general will be paused during the upgrade process. Developers should plan for this downtime and ensure that their applications can handle it.

2. Confirm your Dapp Works on the New Bedrock Goerli Testnet

The Bedrock upgrade will introduce some changes to the way that transactions are processed, including the use of address aliasing for contract deposits. Developers should familiarize themselves with these network-wide changes and ensure that their applications are compatible once the Opt-Goerli testnet is upgraded to Bedrock.

By testing applications on the Bedrock Goerli testnet, developers can ensure their applications will operate as designed when the Optimism Mainnet is upgraded to Bedrock in February.

3. Identify Product Improvements Afforded by Bedrock

The Bedrock upgrade is expected to significantly reduce transaction fees and improve the speed of the network. The upgrade may also introduce new features and capabilities that developers can leverage in their applications. 

The Optimism team created upgrade guides based on application type, which explains the expected impact Bedrock will have on each product type including wallets, frontend/backend engineers, infrastructure providers like Alchemy, and bridge developers.

Optimism Bedrock FAQs

Here are the most frequently asked questions about the Optimism Bedrock upgrade.

How do I upgrade to Bedrock?

If you’re an application developer, there is nothing you need to upgrade. If you are an infrastructure provider, or if you run your own Optimism nodes, follow the Bedrock documentation instructions for infrastructure companies. 

If I use Alchemy, do I need to do anything to support Optimism Bedrock?

No, if you use Alchemy's Optimism RPC node services there is nothing you need to do during the Optimism Bedrock upgrade. Our team of infrastructure specialists will be managing both the testnet upgrade and mainnet upgrades for you.

There will be a 1-hour service pause on Thursday, January 12th, 2023 where the Optimism Goerli testnet will not be able to accept transactions for roughly one hour beginning at 10:00 AM PT while the Optimism team performs the upgrade. To follow along with the network upgrade, visit the Optimism Status page.

Alchemy’s JSON-RPC endpoints for Optimism Goerli will remain the same after the upgrade. You can find the full details on the chain-level changes in Optimism’s Bedrock documentation.

Can I continue to use my existing smart contracts after the Bedrock upgrade?

Some JSON-RPC calls will be deprecated during the Bedrock upgrade including: eth_getBlockRange and rollup_gasPrices. Instead, Optimism developers are encouraged to use eth_getBlockByNumber and eth_gasPrice instead. Lastly, rollup_getInfo will no longer return information on Bedrock.

If your Optimism dapps don’t use the aforementioned JSON-RPC calls, your existing smart contracts and applications should continue to work as normal after the Bedrock upgrade. Before Optimism upgrades their main network, it is always best to validate dapp functionality on the Bedrock Goerli testnet.

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
Layer 2
BEDROCK TESTNET UPGRADE

Optimism Bedrock Testnet Migration Guide (2023)

Learn What the Optimism Bedrock Upgrade is & How to Prepare
Last Updated:
January 12, 2023
Don't miss an update
Sign up for our newsletter to get alpha, key insights, and killer resources.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Table of Contents

Optimism is a layer 2 blockchain that uses optimistic rollups to help Ethereum scale. Optimism is undergoing a network upgrade to Optimism Bedrock, which introduces a series of performance improvements from its existing rollup architecture design. 

This article explains Optimism Bedrock, how it works, and what developers can expect when Optimism upgrades their Goerli testnet on Thursday, January 12th at approximately 10 AM PT, and when the mainnet is planned for upgrade in the weeks to follow.

What is Optimism Bedrock?

Optimism Bedrock is a network-wide upgrade for Optimism nodes that is designed to be the cheapest, fastest, and most advanced rollup architecture available, with support for multiple fault-proof and client implementations.

What improvements does Optimism Bedrock offer?

Optimism Bedrock is expected to bring a number of improvements to the Optimism mainnet. Some of the main changes and improvements that have been mentioned include:

1. Faster Deposit Transactions

Optimism Bedrock will significantly reduce the time required for deposit transactions to 2.5 minutes due to a smaller confirmation depth of 10-12 L1 blocks. This reduces the currently estimated deposit time which is roughly 10 minutes.

2. Lower Gas Fees

Optimism Bedrock introduces new changes to lower gas fees. Optimism Bedrock’s projected transaction fee reduction (20%) is a result of calldata compression and sending transactions to Ethereum using a “non-contract address,.” Besides lowering gas fees, Optimism will also mirror Ethereum’s gas fee design by Supporting EIP-1559.

3. More Predictable Block Production

Optimism Bedrock is expected to produce blocks every two seconds, compared to the current block production rate of 1 block per transaction, the same way Ethereum uses fixed block times.

4. Ethereum Equivalence

Ethereum Equivalence means Optimism Bedrock is designed to be the most seamless rollup possible by dovetailing all of Ethereum's “code, infrastructure, and design patterns,” into the design of Bedrock.

For example, some Ethereum Equivalents in Bedrock include:

What is the Optimism Bedrock migration timeline?

The Optimism Bedrock upgrade involves several steps:

  1. First, deposits and withdrawals will be paused on the legacy network
  2. The legacy sequencer will start rejecting transactions
  3. Then, the smart contracts on L1 will be upgraded and an irregular state transition will be performed on L2
  4. Next, the Bedrock sequencer will be started up.
  5. Finally, deposits and withdrawals will be re-enabled.

The upgrade is expected to result in significantly reduced transaction fees, faster node synchronization, and improved block production. It is not expected to affect everyday users of Optimism, but a mainnet upgrade proposal will be submitted to the Token House for approval after a successful testnet migration.

During both the testnet and mainnet upgrades there will be some downtime from infrastructure providers to upgrade nodes, however transaction history will be maintained.

How should Optimism dapp developers prepare for the Bedrock migration?

During a network-wide migration, developers should:

1. Plan for Downtime

Deposits, withdrawals, and transactions in general will be paused during the upgrade process. Developers should plan for this downtime and ensure that their applications can handle it.

2. Confirm your Dapp Works on the New Bedrock Goerli Testnet

The Bedrock upgrade will introduce some changes to the way that transactions are processed, including the use of address aliasing for contract deposits. Developers should familiarize themselves with these network-wide changes and ensure that their applications are compatible once the Opt-Goerli testnet is upgraded to Bedrock.

By testing applications on the Bedrock Goerli testnet, developers can ensure their applications will operate as designed when the Optimism Mainnet is upgraded to Bedrock in February.

3. Identify Product Improvements Afforded by Bedrock

The Bedrock upgrade is expected to significantly reduce transaction fees and improve the speed of the network. The upgrade may also introduce new features and capabilities that developers can leverage in their applications. 

The Optimism team created upgrade guides based on application type, which explains the expected impact Bedrock will have on each product type including wallets, frontend/backend engineers, infrastructure providers like Alchemy, and bridge developers.

Optimism Bedrock FAQs

Here are the most frequently asked questions about the Optimism Bedrock upgrade.

How do I upgrade to Bedrock?

If you’re an application developer, there is nothing you need to upgrade. If you are an infrastructure provider, or if you run your own Optimism nodes, follow the Bedrock documentation instructions for infrastructure companies. 

If I use Alchemy, do I need to do anything to support Optimism Bedrock?

No, if you use Alchemy's Optimism RPC node services there is nothing you need to do during the Optimism Bedrock upgrade. Our team of infrastructure specialists will be managing both the testnet upgrade and mainnet upgrades for you.

There will be a 1-hour service pause on Thursday, January 12th, 2023 where the Optimism Goerli testnet will not be able to accept transactions for roughly one hour beginning at 10:00 AM PT while the Optimism team performs the upgrade. To follow along with the network upgrade, visit the Optimism Status page.

Alchemy’s JSON-RPC endpoints for Optimism Goerli will remain the same after the upgrade. You can find the full details on the chain-level changes in Optimism’s Bedrock documentation.

Can I continue to use my existing smart contracts after the Bedrock upgrade?

Some JSON-RPC calls will be deprecated during the Bedrock upgrade including: eth_getBlockRange and rollup_gasPrices. Instead, Optimism developers are encouraged to use eth_getBlockByNumber and eth_gasPrice instead. Lastly, rollup_getInfo will no longer return information on Bedrock.

If your Optimism dapps don’t use the aforementioned JSON-RPC calls, your existing smart contracts and applications should continue to work as normal after the Bedrock upgrade. Before Optimism upgrades their main network, it is always best to validate dapp functionality on the Bedrock Goerli testnet.

Optimism is a layer 2 blockchain that uses optimistic rollups to help Ethereum scale. Optimism is undergoing a network upgrade to Optimism Bedrock, which introduces a series of performance improvements from its existing rollup architecture design. 

This article explains Optimism Bedrock, how it works, and what developers can expect when Optimism upgrades their Goerli testnet on Thursday, January 12th at approximately 10 AM PT, and when the mainnet is planned for upgrade in the weeks to follow.

What is Optimism Bedrock?

Optimism Bedrock is a network-wide upgrade for Optimism nodes that is designed to be the cheapest, fastest, and most advanced rollup architecture available, with support for multiple fault-proof and client implementations.

What improvements does Optimism Bedrock offer?

Optimism Bedrock is expected to bring a number of improvements to the Optimism mainnet. Some of the main changes and improvements that have been mentioned include:

1. Faster Deposit Transactions

Optimism Bedrock will significantly reduce the time required for deposit transactions to 2.5 minutes due to a smaller confirmation depth of 10-12 L1 blocks. This reduces the currently estimated deposit time which is roughly 10 minutes.

2. Lower Gas Fees

Optimism Bedrock introduces new changes to lower gas fees. Optimism Bedrock’s projected transaction fee reduction (20%) is a result of calldata compression and sending transactions to Ethereum using a “non-contract address,.” Besides lowering gas fees, Optimism will also mirror Ethereum’s gas fee design by Supporting EIP-1559.

3. More Predictable Block Production

Optimism Bedrock is expected to produce blocks every two seconds, compared to the current block production rate of 1 block per transaction, the same way Ethereum uses fixed block times.

4. Ethereum Equivalence

Ethereum Equivalence means Optimism Bedrock is designed to be the most seamless rollup possible by dovetailing all of Ethereum's “code, infrastructure, and design patterns,” into the design of Bedrock.

For example, some Ethereum Equivalents in Bedrock include:

What is the Optimism Bedrock migration timeline?

The Optimism Bedrock upgrade involves several steps:

  1. First, deposits and withdrawals will be paused on the legacy network
  2. The legacy sequencer will start rejecting transactions
  3. Then, the smart contracts on L1 will be upgraded and an irregular state transition will be performed on L2
  4. Next, the Bedrock sequencer will be started up.
  5. Finally, deposits and withdrawals will be re-enabled.

The upgrade is expected to result in significantly reduced transaction fees, faster node synchronization, and improved block production. It is not expected to affect everyday users of Optimism, but a mainnet upgrade proposal will be submitted to the Token House for approval after a successful testnet migration.

During both the testnet and mainnet upgrades there will be some downtime from infrastructure providers to upgrade nodes, however transaction history will be maintained.

How should Optimism dapp developers prepare for the Bedrock migration?

During a network-wide migration, developers should:

1. Plan for Downtime

Deposits, withdrawals, and transactions in general will be paused during the upgrade process. Developers should plan for this downtime and ensure that their applications can handle it.

2. Confirm your Dapp Works on the New Bedrock Goerli Testnet

The Bedrock upgrade will introduce some changes to the way that transactions are processed, including the use of address aliasing for contract deposits. Developers should familiarize themselves with these network-wide changes and ensure that their applications are compatible once the Opt-Goerli testnet is upgraded to Bedrock.

By testing applications on the Bedrock Goerli testnet, developers can ensure their applications will operate as designed when the Optimism Mainnet is upgraded to Bedrock in February.

3. Identify Product Improvements Afforded by Bedrock

The Bedrock upgrade is expected to significantly reduce transaction fees and improve the speed of the network. The upgrade may also introduce new features and capabilities that developers can leverage in their applications. 

The Optimism team created upgrade guides based on application type, which explains the expected impact Bedrock will have on each product type including wallets, frontend/backend engineers, infrastructure providers like Alchemy, and bridge developers.

Optimism Bedrock FAQs

Here are the most frequently asked questions about the Optimism Bedrock upgrade.

How do I upgrade to Bedrock?

If you’re an application developer, there is nothing you need to upgrade. If you are an infrastructure provider, or if you run your own Optimism nodes, follow the Bedrock documentation instructions for infrastructure companies. 

If I use Alchemy, do I need to do anything to support Optimism Bedrock?

No, if you use Alchemy's Optimism RPC node services there is nothing you need to do during the Optimism Bedrock upgrade. Our team of infrastructure specialists will be managing both the testnet upgrade and mainnet upgrades for you.

There will be a 1-hour service pause on Thursday, January 12th, 2023 where the Optimism Goerli testnet will not be able to accept transactions for roughly one hour beginning at 10:00 AM PT while the Optimism team performs the upgrade. To follow along with the network upgrade, visit the Optimism Status page.

Alchemy’s JSON-RPC endpoints for Optimism Goerli will remain the same after the upgrade. You can find the full details on the chain-level changes in Optimism’s Bedrock documentation.

Can I continue to use my existing smart contracts after the Bedrock upgrade?

Some JSON-RPC calls will be deprecated during the Bedrock upgrade including: eth_getBlockRange and rollup_gasPrices. Instead, Optimism developers are encouraged to use eth_getBlockByNumber and eth_gasPrice instead. Lastly, rollup_getInfo will no longer return information on Bedrock.

If your Optimism dapps don’t use the aforementioned JSON-RPC calls, your existing smart contracts and applications should continue to work as normal after the Bedrock upgrade. Before Optimism upgrades their main network, it is always best to validate dapp functionality on the Bedrock Goerli testnet.

Build web3 with Alchemy

Alchemy combines the most powerful web3 developer products and tools with resources, community and legendary support.

Get started for free