Can You Add Arbitrum to MetaMask?

Yes. Arbitrum mirrors Ethereum at the bytecode level, so MetaMask connects to it exactly as it does to mainnet. The wallet ships with Ethereum selected and treats any other chain as a custom entry you define with an RPC endpoint and a chain ID.

Arbitrum is three live networks, not one. Arbitrum One is the flagship rollup with nearly all the liquidity and apps; Arbitrum Nova is a cheaper chain for games and social apps; Arbitrum Sepolia is the public testnet, used to trial contracts with valueless ETH. Each has its own chain ID, so adding one does not add the others. Pick the one that fits your goal.

How to Add Arbitrum One to MetaMask

ChainList is a registry of EVM-compatible networks that reads your wallet and configures the chain for you, ruling out a mistyped RPC URL or an endpoint copied from a shady source. For Arbitrum One, it is the fastest path:

1. Open ChainList: Go to the Arbitrum One page on ChainList and select "Connect Wallet."
2. Approve access: Confirm in MetaMask, checking you are linking the right account.
3. Add the network: Click "Add to MetaMask" on the Arbitrum One entry. The RPC URL, chain ID, symbol, and explorer fill in automatically.
4. Confirm: Approve the prompt, then select Arbitrum One from the network dropdown.

Arbitrum One RPC and Chain ID

To set up Arbitrum One without a third-party tool, open MetaMask, choose "Add a network manually" from the network menu, and enter the values below, as published in the official Arbitrum docs:

• Network Name: Arbitrum One
• RPC URL: https://arb1.arbitrum.io/rpc
• Chain ID: 42161
• Currency Symbol: ETH
• Block Explorer URL: https://arbiscan.io

Arbitrum's public RPC carries no uptime or rate-limit guarantees, so treat it as a starting point. For anything demanding, such as a bot, dashboard, or production app, point MetaMask at a dedicated endpoint from Alchemy, Infura, or QuickNode and keep the public URL as backup.

Arbitrum Nova RPC and Chain ID

Nova makes a trade-off. Rather than posting all transaction data to Ethereum, it uses an AnyTrust model that delegates data availability to a named committee. That cuts fees further, which suits high-frequency, low-value activity like onchain games and social apps over large DeFi positions.

• Network Name: Arbitrum Nova
• RPC URL: https://nova.arbitrum.io/rpc
• Chain ID: 42170
• Currency Symbol: ETH
• Block Explorer URL: https://nova.arbiscan.io

If you mainly want Arbitrum's DeFi and trading apps, stick with Arbitrum One. Nova is the specialist.

Adding the Arbitrum Sepolia Testnet

Arbitrum Sepolia is Arbitrum's public testnet, a free sandbox that mirrors Arbitrum One so you can deploy and trial smart contracts before committing them to mainnet. It settles to Ethereum's Sepolia and runs on valueless test ETH. Adding it to MetaMask works like any other network: use ChainList for one-click setup, or enter the details manually.

Add Arbitrum Sepolia with the values below, taken from Arbitrum's public chains reference:

• Network Name: Arbitrum Sepolia
• RPC URL: https://sepolia-rollup.arbitrum.io/rpc
• Chain ID: 421614
• Currency Symbol: ETH
• Block Explorer URL: https://sepolia.arbiscan.io

Retired Arbitrum Testnets

Sepolia is the only testnet Arbitrum still supports, so ignore the retired ones that older tutorials reference:

• Arbitrum Goerli was deprecated in November 2023 and shut down on March 18, 2024, when Ethereum retired Goerli.
• RinkArby, the original Rinkeby-based testnet, was retired back in December 2022.
• The standalone Stylus testnet closed in June 2024 once Stylus shipped on Arbitrum One and Sepolia, so no separate chain is needed to build with it.

About Arbitrum

Arbitrum is an Ethereum layer 2 from Offchain Labs and the largest rollup by total value locked. As an optimistic rollup, it executes transactions off Ethereum and posts them back in compressed batches, treated as valid unless challenged within a dispute window. That keeps fees low while Ethereum handles settlement.

One catch: native withdrawals to Ethereum clear only after a challenge period of about a week, so most users bridge off Arbitrum through third-party liquidity instead. You pay gas in ETH, while the ARB token, airdropped in March 2023, is for Arbitrum DAO governance, not transactions. The Nitro stack powers One, Nova, and Sepolia alike.

Recent upgrades push the network well past cheap transactions:

• Stylus lets developers write contracts in Rust, C, C++, or any WebAssembly language, running them in a second VM beside the EVM that interoperates with Solidity. It is live on Arbitrum One and Sepolia, widening the builder pool beyond Solidity.
• Orbit is a launchpad for custom layer 2s and 3s built on Arbitrum tech, now underpinning more than a hundred chains, including Robinhood's planned chain for tokenized stocks.
• BoLD opened fraud-proof validation to anyone, lifting Arbitrum to Stage 1 decentralization on L2BEAT, with Stage 2 next.
• Timeboost, added in 2025, orders transactions so the network captures MEV transparently instead of letting it leak out.

The aim is to be settlement infrastructure for DeFi, real-world assets, and gaming, not just a cheap Ethereum. Its closest rival is Coinbase-backed Base, which leads on daily activity while Arbitrum holds the TVL lead; together they hold most layer 2 liquidity.

Bottom Line

Adding Arbitrum to MetaMask takes about a minute.

Let ChainList configure Arbitrum One, or enter the RPC details by hand to keep wallet permissions tight. Choose the right network for the job - Arbitrum One for DeFi and trading, Nova for low-cost gaming and social apps, Sepolia for testing.

Confirm the chain ID and RPC against an official source first, and you are set to explore one of Ethereum's deepest onchain economies.