EVM chain

Arbitrum One — RPC URL, Chain ID, and Wallet Setup

Arbitrum One mainnet has chain ID 42161 and uses ether (ETH) as its native currency. The official RPC URL maintained by Offchain Labs is https://arb1.arbitrum.io/rpc, the documentation lives at docs.arbitrum.io, and the block explorer is arbiscan.io.

Chain ID 42161Native ETHMainnetVerified 2026-05-15

Quick reference

Copy paste ready values. Verified on 2026-05-15.

Chain name
Arbitrum One
Chain ID
42161 (hex 0xa4b1)
Network type
Mainnet
Native currency
Ether (ETH) — 18 decimals
Recommended public RPC
https://arb1.arbitrum.io/rpc
Block explorer
https://arbiscan.io
Official docs
https://docs.arbitrum.io/
Last verified
2026-05-15

Add Arbitrum One to MetaMask

One click for injected wallets, or paste the JSON into the manual Add Network form.

{
  "chainIdHex": "0xa4b1",
  "chainName": "Arbitrum One",
  "nativeCurrency": {
    "name": "Ether",
    "symbol": "ETH",
    "decimals": 18
  },
  "rpcUrls": [
    "https://arb1.arbitrum.io/rpc"
  ],
  "blockExplorerUrls": [
    "https://arbiscan.io"
  ]
}
Manual steps (no injected wallet)
  1. Open MetaMask, click the network dropdown, then Add Network.
  2. Click "Add a network manually".
  3. Network name: Arbitrum One.
  4. New RPC URL: https://arb1.arbitrum.io/rpc.
  5. Chain ID: 42161.
  6. Currency symbol: ETH.
  7. Block explorer URL: https://arbiscan.io.
  8. Save and switch.

Free / public RPC URLs

Public RPC URLs for Arbitrum One

These endpoints are free, anonymous, and rate limited. They are useful for development, wallet reads, and one off scripts. For production traffic or indexer workloads, pair them with a paid provider so the public list becomes your fallback rather than your primary.

RPC URLHosted byNotes
https://arb1.arbitrum.io/rpcOffchain Labs (official)Recommended in official docs.
https://arbitrum-one-rpc.publicnode.comAllnodes (publicnode) WebSocket: wss://arbitrum-one-rpc.publicnode.com.
https://rpc.ankr.com/arbitrumAnkr
https://arbitrum.drpc.orgdRPC
https://1rpc.io/arb1RPC
https://arbitrum-one.public.blastapi.ioBware Labs (BlastAPI)

Paid RPC providers

Production dapps, indexers, and trading systems should use a managed provider with a private API key, archive history, and an SLA. These providers list Arbitrum One support on their public pricing pages.

  • Alchemy

    Supernode RPC plus enhanced APIs across 40+ chains.

    Free tier: 30M compute units per month on the Free plan.

  • Infura

    ConsenSys backed RPC, deeply integrated with MetaMask.

    Free tier: 6M credits per day, ~2,000 credits per second throughput.

  • QuickNode

    Globally distributed RPC across 50+ chains.

    Free tier: Seven day free trial with full feature access.

  • Ankr

    Public RPC for 80+ chains plus a Premium tier.

    Free tier: Free public endpoints (rate limited) for 80+ chains, no signup required.

  • GetBlock

    Shared and dedicated nodes across 50+ chains.

    Free tier: Free plan with a daily request cap shared across chains.

  • BlockPI

    Pay as you go RPC with no monthly minimums.

    Free tier: Free public endpoints per chain with shared rate limits.

  • Chainstack

    Region selectable elastic and dedicated nodes.

    Free tier: Free Developer plan with 3M requests per month.

  • Tenderly

    RPC with first class simulation and debugging.

    Free tier: Free plan with simulator access and a small RPC quota.

  • dRPC

    Decentralised RPC across 100+ chains.

    Free tier: Free public endpoints per chain plus a generous metered free tier.

  • NodeReal

    MegaNode RPC with deep BNB Chain support.

    Free tier: Free plan with 3M compute units per day.

Compare every paid RPC provider →

Block explorers and docs

Arbitrum One explorers and documentation

When the answer is real

Caveats and things to verify

  • Arbitrum One uses a single sequencer operated by Offchain Labs. There is a delayed inbox so users can force include transactions, but the live UX still depends on the sequencer.
  • Some Ethereum opcodes behave differently on Arbitrum. Always read the Arbitrum solidity quirks page before porting a contract.
  • Withdrawals to Ethereum mainnet take ~7 days due to the optimistic rollup challenge window. Use a third party bridge for faster exits.

FAQ

Frequently asked questions

What is the Arbitrum One chain ID?

Arbitrum One mainnet chain ID is 42161 (hex 0xa4b1). The Arbitrum Sepolia testnet is chain ID 421614. Arbitrum Nova is a separate chain with chain ID 42170.

What is the official Arbitrum One RPC URL?

The official RPC maintained by Offchain Labs is https://arb1.arbitrum.io/rpc. It is the endpoint listed in the Arbitrum docs and in the ethereum-lists/chains canonical JSON. For production loads, prefer a managed provider such as Alchemy, Infura, or QuickNode.

How do I add Arbitrum One to MetaMask?

In MetaMask, click the network dropdown, then Add Network, then Add a network manually. Paste Network name Arbitrum One, RPC URL https://arb1.arbitrum.io/rpc, chain ID 42161, currency symbol ETH, and block explorer https://arbiscan.io. Save and switch.

What is the native currency of Arbitrum One?

Ether (ETH). Arbitrum bridges native ETH from Ethereum mainnet so gas fees are paid in ETH, not in a separate Arbitrum token. ARB is the governance token but is not used for gas.

What are the best paid RPC providers for Arbitrum?

Alchemy, Infura, QuickNode, Ankr, Chainstack, BlockPI, Tenderly, dRPC, and GetBlock all support Arbitrum One. Alchemy and QuickNode are popular for production traffic. Tenderly is the choice if you rely on transaction simulation and debugging. Public endpoints are fine for reads but should not be used for write traffic.

Is Arbitrum One an Ethereum Layer 2?

Yes. Arbitrum One is an optimistic rollup that posts compressed transaction data to Ethereum mainnet and uses fraud proofs (with the BoLD upgrade) for security. Withdrawals to Ethereum take roughly seven days because of the challenge window.

Sources

Wallet setup walkthrough

Step by step screenshots and copy paste blocks for adding Arbitrum One to MetaMask, Rabby, and OKX Wallet.

Open the Arbitrum One wallet setup guide →

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Page maintained by Mudassir Khan · Last verified 2026-05-15.