This guide shows how to connect Arbitrum to MetaMask and covers both the one-click method from arbitrum.foundation and the manual RPC route. If you use MetaMask as your hot wallet for DeFi activity, adding Arbitrum lets you interact with Arbitrum dApps, swap tokens at lower L2 gas fees, and use EVM-compatible tooling without changing your existing key management.
Why add Arbitrum to MetaMask? Lower gas fees and faster confirmations for many DeFi tasks. Short answer. Longer answer: Arbitrum is an EVM-compatible Layer 2 that accepts the same addresses and many of the same smart contracts you already use on Ethereum mainnet, so MetaMask becomes a single place to manage activity across chains.
I've been using Arbitrum on MetaMask daily for months and it usually saves on gas when swapping or interacting with protocols. But remember: lower fees do not mean no risk.
https://arbitrum.foundation (check the padlock).Tip: when prompted, confirm the chain ID is 42161 (decimal) or 0xA4B1 (hex). If the numbers don't match, cancel and double-check the site. I believe this step prevents many spoofing attempts.
(If you prefer not to use the one-click flow, follow the manual steps below.)
Open MetaMask in your browser (extension).
Click the network dropdown at the top of the extension and choose Add network or Add a network (this opens the custom network form).
Fill the network fields with the following values:
0xA4B1)Save and switch to the new network.
You should now see your account address and be able to send/receive ETH on Arbitrum. If you need to move assets from Ethereum mainnet, use an audited bridge (see bridges and cross-chain guides).
![Screenshot placeholder: MetaMask add network form]
Alternate mobile path: use the MetaMask in-app browser to visit arbitrum.foundation and tap Connect. The app will prompt to add the network automatically. But check the chain ID before approving.
And if you switch phones, follow recovery steps in backup and recovery to restore access — never share your seed phrase.
Short answer: pick the form factor that fits your workflow. Need to interact with browser-based dApps on desktop? Use the extension. Mostly on the go and tapping links? Use mobile.
| Feature | Desktop extension | Mobile app |
|---|---|---|
| Injected provider for web dApps | Yes (injected) | Limited (in-app browser) |
| WalletConnect support | Yes | Yes (common for mobile dApps) |
| Hardware wallet integration | Yes (Ledger, Trezor via extension) | Limited (mobile bridges) |
| In-app dApp browser | No | Yes |
| Easy network switching | Yes (network dropdown) | Yes (settings) |
Both are non-custodial and use the same seed phrase / accounts if you restore them. But the extension makes desktop DeFi work smoother; mobile is better for quick approvals and WalletConnect sessions.
0xA4B1 when a site asks to add Arbitrum.In my experience the most common slip-up is approving a contract while on the wrong network. Double-check the network name in the top bar before you sign transactions.
If a site repeatedly asks to add networks with strange chain IDs, close the tab and clear browser cache. For dApp connection issues see [/troubleshooting-dapp-connections].
Who this setup is best for
Who should look elsewhere
Q: Is it safe to keep crypto in a hot wallet?
A: Hot wallets are convenient for daily use, but they are exposed online. I use a hot wallet for day-to-day DeFi actions and move long-term holdings to hardware or multisig for storage. Treat your seed phrase like a vault key: offline, hidden, and never pasted into a website.
Q: How do I revoke token approvals on Arbitrum?
A: Connect MetaMask to Arbitrum, then use a permission management tool or the token approvals page referenced above (/token-approvals-revoke). These tools list allowances per contract and let you revoke or reduce them. Double-check you're on Arbitrum before making changes.
Q: What happens if I lose my phone?
A: Restore your wallet on a new device using your seed phrase or private keys. See backup and recovery for step-by-step restore procedures. But be careful: if someone else has your seed phrase, they can restore and drain funds.
Adding Arbitrum to MetaMask is a straightforward way to reduce gas on common DeFi actions and access L2 dApps from the same accounts you already use. If you want to learn more about Layer 2 gas mechanics or adding other networks, check layer2 networks and gas fees and L2. For setup help, see install the MetaMask extension or install the MetaMask mobile app.
If you're ready to connect via the site, remember to confirm chain ID 42161 before approving. And if you run into a hiccup, troubleshooting steps are above — or visit the linked pages for deeper guidance.
Safe signing, and happy testing on Arbitrum.