How to Add Arbitrum to MetaMask: Quick Setup Guide

Adding Arbitrum One to MetaMask means entering its network details — chain ID 42161, RPC URL, currency symbol, and block explorer — either automatically through a one-click prompt on many dapp sites or manually through MetaMask's network settings.

The easiest method: one-click add

Many Arbitrum-based dapps, including the official Arbitrum Bridge, will automatically prompt MetaMask to add the network the first time you connect your wallet and attempt a transaction on it. If you see a "Add Arbitrum Network" or "Switch Network" prompt from a site you trust and have verified is genuine, approving it is the fastest way to get set up correctly, since it fills in all the network details automatically without any manual entry.

Manual setup steps

If you prefer to add it manually, or a one-click prompt isn't available:

1. Open MetaMask and click the network selector at the top of the interface.
2. Select "Add network", then "Add a network manually."
3. Enter the following details:

Field	Value
Network name	Arbitrum One
New RPC URL	https://arb1.arbitrum.io/rpc
Chain ID	42161
Currency symbol	ETH
Block explorer URL	https://arbiscan.io

4. Save the network, then switch to it using the network selector.

Always type or verify these details against Arbitrum's own official documentation rather than copying them from an unverified source — a malicious RPC endpoint could theoretically be used to feed your wallet false information, though it cannot steal funds on its own without you separately approving a malicious transaction.

Verifying you're actually on Arbitrum

Once added, confirm the network is working correctly by checking that your wallet shows an ETH balance consistent with what you expect on Arbitrum (zero if you haven't bridged yet), and that a test transaction — even just viewing your address on the Arbiscan block explorer — matches what you see in your wallet.

Getting funds onto the network

Adding the network to MetaMask doesn't move any funds — you'll still need to bridge assets from Ethereum mainnet or another supported chain. Our full walkthrough is in how to bridge to Arbitrum.

Common issues and fixes

• "Network already exists" error: MetaMask may have already auto-added a version of the network from a previous dapp interaction; check your existing network list before adding a duplicate.
• RPC not responding: public RPC endpoints occasionally experience downtime; if https://arb1.arbitrum.io/rpc isn't responding, check Arbitrum's official documentation for alternative public RPC providers.
• Balance shows zero after bridging: confirm the bridging transaction actually finalized on Arbitrum (check the transaction hash on Arbiscan) before assuming something is wrong with your MetaMask setup.
• Wrong chain ID entered: double-check you entered 42161 exactly — a typo here will either fail to save or connect to an unintended network.

A note on alternative wallets

While this guide focuses on MetaMask, since it remains one of the most widely used wallets for interacting with Ethereum L2s, the same chain ID, RPC, and explorer details apply if you're setting up Arbitrum in a different wallet — most wallets support the same "add custom network" workflow with equivalent fields, even if the menu layout differs. If your wallet supports importing network lists from a standard registry, that can be a faster and less error-prone alternative to typing details manually, provided the registry itself is from a source you trust.

What you can do once connected

With Arbitrum added and funds bridged over, you can start exploring its DeFi ecosystem — decentralized exchanges, lending markets, and perpetuals platforms that have deployed there for its lower fees relative to Ethereum mainnet. See our full guide to DeFi on Arbitrum for an overview of what's available, and review DeFi wallet security basics if you're newer to self-custody.

Adding Arbitrum Nova instead of Arbitrum One

If you specifically need Arbitrum Nova rather than the main Arbitrum One chain — for example, to use a specific gaming or social application built there — it requires its own separate network entry in MetaMask, with a different chain ID and RPC endpoint from Arbitrum One. The two chains are not interchangeable, and assets bridged to one won't automatically appear on the other, so confirm which specific chain a given application actually requires before adding a network and bridging funds.

Bottom line

Adding Arbitrum One to MetaMask takes just a couple of minutes, whether through a one-click dapp prompt or manual entry of its chain ID (42161) and RPC details. Getting the network added is only the first step, though — you'll still need to bridge funds over before you can actually use any Arbitrum-based DeFi protocol.