In this Optimism tutorial, we will explain how to use Optimism L2, connect Optimism to MetaMask and how to bridge ETH to Optimistic Ethereum

Optimism Layer 2 Tutorial

What is Optimism & Layer 2?

Optimism similar to Arbitrum & Polygon is a Layer 2 scaling solution for Ethereum that supports Ethereum’s Dapps.  The Optimistic Ethereum network lets you send transactions, similar to Ethereum, but with two main advantages which are fast transaction speeds and lower transaction fees.

It does this by running all transaction data on-chain and runs computation off-chain which then increases Ethereum’s transactions per second and decreases the fees. 

How to Connect Metamask to Optimistic Ethereum

To connect to Optimism, you’ll first need to have a wallet that supports and connects to Optimistic Ethereum. If you are using Metamask and it’s not yet available from your list of networks, follow the below steps to add Optimistic Ethereum to your Metamask account.

  • Open your Metamask web extension
  • Click onto the dropdown at the top of the wallet (if Optimistic Ethereum is not appearing in your list choose “Custom RPC”)
  • Add the following details:

Network Name: Optimistic Ethereum

New RPC URL: https://mainnet.optimism.io

Chain ID: 10

Symbol: ETH

Block Explorer URL: https://optimistic.ethereum.io

  • Click “Save” and you’ll be automatically connected to the Optimistic Ethereum network.

Alternatively, to integrate Optimistic Ethereum automatically, head across to Chainlink’s page for Optimistic Ethereum using the link https://chainid.link/?network=optimism, then simply choose to “Connect“, and then approve the changes in MetaMask.

To start storing Optimistic Ethereum tokens in your wallet, you’ll first need to bridge your Ethereum, ERC20 tokens to Optimistic Ethereum.

add optimistic ethereum network to metamask
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How to Bridge Ethereum to Optimistic Ethereum

To get started using Optimism, you’ll need to deposit your Ethereum based tokens from the Ethereum mainnet across to Optimistic Ethereum, using a bridge. Also known as the Optimistic Ethereum Gateway which you can find on the Optimism.io site (under Tools).

Before using the gateway, please be aware that Optimism Etheruem is still a very new protocol and to use at your own risk. Also, any withdrawals from Optimistic Ethereum to standard Ethereum mainnet will require a wait time of a week.

If you don’t already have any Etheruem to get started with, you can purchase some on popular cryptocurrency exchanges such as Binance, FTX or Huobi with either cryptocurrency or FIAT.

  • Connect your web3 wallet (which will need to be connected to the Ethereum mainnet)
  • Once connected, ensure you are on the “Deposit” tab and ‘From’ is showing “MAINNET
  • Select the token that you are bridging from and enter the amount, you want to bridge.
  • Ensure that ‘To’ is showing “OPTIMISTIC ETHEREUM
bridging ETH to Optimism
  • Choose “Deposit
  • Approve the transaction, please just be aware that deposits can take about 20 minutes before they’re considered final on Optimistic Ethereum.
  • Choose ” Deposit” and “Confirm” the transaction in your wallet.

Once your tokens have finalised bridging on Optimistic Ethereum, they should then be appearing in our connected wallet, under “Optimistic Ethereum“.

Ethereum DApps Supporting Optimism

Optimistic Ethereum can support any Etherem app. Some of the most popular platforms on Optimistic Ethereum (at the time of writing this Optimism review) are Uniswap, Synthetix and 1inch.

When creating our Optimism tutorial, I used an example of trading 0.5ETH for USDT on the Uniswap platform using both the Ethereum mainnet and Optimism. Using the Ethereum mainnet the transaction cost was $73.00. However, when making the same swap on Optimism the fee was just $4.71.