Guide to add Arbitrum Mainnet and Testnet as custom MetaMask RPC.
Arbitrum is an Optimistic Rollup and has made its name one of the top Layer 2 solutions on Ethereum. This section will include ways to add Arbitrum Mainnet and Testnet as your custom MetaMask RPC node.
Open Metamask and click the network name located at the top-right of the window
Click the Add Network button at the bottom of the pop-up window
Enter the following network details and click Save
Network Name: Arbitrum or Arbitrum One
You can name your Network Name anything to remind you which chain you’re connecting to.