What is the Arbitrum One mainnet RPC URL?

Arbitrum One's listed primary public RPC URL is https://arb1.arbitrum.io/rpc.

What is Arbitrum One's chain ID?

Arbitrum One's listed chain ID is 42161.

What block explorer does Arbitrum One use?

Arbitrum One's listed block explorer is https://arbiscan.io.

What gas token does Arbitrum One use?

Arbitrum One's listed gas token is ETH.

Chain profile

Arbitrum One chain ID 42161, RPC URL, and explorer

Source snapshotJuly 4, 2026

Source evidence snapshot July 4, 2026. Arbitrum One mainnet uses chain ID 42161 / 0xa4b1, RPC URL https://arb1.arbitrum.io/rpc, explorer https://arbiscan.io, and ETH as the gas token. Use this page to copy the fields, open source evidence, and check setup cautions before use.

Quick settings

Arbitrum chain ID answer

Arbitrum One mainnet uses chain ID 42161 / 0xa4b1, RPC URL https://arb1.arbitrum.io/rpc, explorer https://arbiscan.io, and ETH as the gas token. Copy the fields below and verify them against the linked source docs before using them in a wallet, script, or app.

Chain ID: 42161 / 0xa4b1
RPC URL: https://arb1.arbitrum.io/rpc
Explorer: https://arbiscan.io
Gas token: ETH
Source docs: Arbitrum docs
Latest check: Jul 20, 2026
Source snapshot: July 4, 2026
Config path: wallet_addEthereumChain JSON

Copy Arbitrum One config Open Arbitrum One guide Explorer directory Gas token directory

Good fit when you need:

the Arbitrum One chain ID, RPC URL, explorer, and gas token in one place;
source documentation links beside the copied setup fields;
manual wallet config fields without connecting a wallet or choosing an RPC provider.

Before you paste these fields:

compare the chain ID against the source link on this page;
open the explorer once and confirm it matches the network you expect;
use the public RPC for setup checks, then choose monitored infrastructure for production traffic.

Exact setup guide

Arbitrum One chain ID and RPC guide

Open this guide when you specifically need chain ID, RPC URL, explorer, gas token, or wallet configfor Arbitrum One. It keeps the copied fields, official/source docs, and setup cautions together in one focused reference.

Open Arbitrum One chain ID and RPC guide Chain ID list Mainnet RPC list

Chain ID42161 / 0xa4b1

RPC URLhttps://arb1.arbitrum.io/rpc

Explorerhttps://arbiscan.io

Gas tokenETH

VerificationVerified metadata

Source snapshotJuly 4, 2026

Evidence snapshotJul 20, 2026

Verification record

Automated source snapshots and recorded probe evidence are tracked separately. The source snapshot timestamp is not a manual review date. This is not a live uptime, latency, or production reliability monitor. If a recorded public RPC probe fails, verify the source links and current endpoint availability before changing production configuration.

Automated source snapshot: July 4, 2026
Verification status: Verified metadata
Source snapshot run: source-monitoring-2026-07-04
Source snapshot tool: source-monitoring-refresh
Source set: Arbitrum docs
Latest recorded chain ID probe: eth_chainId matched expected 0xa4b1; observed 0xa4b1 on Jul 20, 2026

Methodology Report a correction

Arbitrum One wallet-add fields

Wallet directory sites often expose a connect button. Main.net keeps the same MetaMask and EIP-3085 setup fields as text so developers can compare them with official/source docs before calling wallet_addEthereumChain.

chainId: 0xa4b1 (42161)
chainName: Arbitrum One
nativeCurrency: ETH; name ETH, symbol ETH, decimals 18
rpcUrls: https://arb1.arbitrum.io/rpc
blockExplorerUrls: https://arbiscan.io

GlossaryChain IDHow wallet and RPC software identify a mainnet network.GlossaryRPC endpointWhat an RPC URL does and why public endpoints can be rate-limited.GlossaryMainnetThe production network context for these chain settings.Gas tokenETH gas tokenOther mainnet rows that use ETH for gas.Network categoryEVM mainnetsCompare Arbitrum One with related evm mainnets by chain ID, RPC URL, explorer, and source links.Network categoryL2 mainnetsCompare Arbitrum One with related l2 mainnets by chain ID, RPC URL, explorer, and source links.GuideArbitrum One chain ID and RPC guideArbitrum One-specific chain ID, RPC URL, explorer, gas token, and wallet setup reference.

Monitoring evidence

These checks are review signals only. They are not uptime, latency, privacy, or production reliability claims. A source fetch failure or eth_chainId failure can mean a source page or public RPC endpoint was unavailable, changed, or rate-limited during a check. Re-open source links and test current RPC availability before relying on a public endpoint.

Snapshot generated: Jul 20, 2026
Source checks: 1 sources checked
Source changes: 0 changes since the previous source hash snapshot
Source fetch failures: 0
eth_chainId probe: matched expected 0xa4b1
Per-source check timing: Included in the monitoring snapshot, not represented as a manual review or page freshness date

View monitoring snapshots orsource change history.

Network endpoints

Primary public RPC: https://arb1.arbitrum.io/rpc
Explorer: https://arbiscan.io
Official/source documentation: Arbitrum docs
Chain type: Optimistic L2 mainnet
Chain ID hex: 0xa4b1
Source snapshot provenance: source-monitoring-2026-07-04 via source-monitoring-refresh

Arbitrum One common questions

What is the Arbitrum One mainnet RPC URL?: Arbitrum One's listed primary public RPC URL is https://arb1.arbitrum.io/rpc.
What is Arbitrum One's chain ID?: Arbitrum One's listed chain ID is 42161.
What block explorer does Arbitrum One use?: Arbitrum One's listed block explorer is https://arbiscan.io.
What gas token does Arbitrum One use?: Arbitrum One's listed gas token is ETH.

Copy-ready config

Neutral app configuration built from the verified fields above. Copy buttons only place text on your clipboard; they do not connect a wallet, request permissions, or rank RPC providers.

Chain ID decimal42161

Chain ID hex0xa4b1

RPC URLhttps://arb1.arbitrum.io/rpc

Explorer URLhttps://arbiscan.io

EIP-3085-shaped JSON

Rendered as text for manual review before use.

{
  "chainId": "0xa4b1",
  "chainName": "Arbitrum One",
  "nativeCurrency": {
    "name": "ETH",
    "symbol": "ETH",
    "decimals": 18
  },
  "rpcUrls": [
    "https://arb1.arbitrum.io/rpc"
  ],
  "blockExplorerUrls": [
    "https://arbiscan.io"
  ]
}

Developer snippets

Static examples generated from Main.net fields. These snippets are for manual configuration review and read-only RPC checks; they do not connect wallets, create signers, submit writes, or rank providers.

viem chain definition

Read-only snippet generated from Main.net fields. Review official sources before production use.

import { defineChain } from 'viem'

export const arbitrumOneMainnet = defineChain({
  id: 42161,
  name: "Arbitrum One",
  nativeCurrency: {
    name: "ETH",
    symbol: "ETH",
    decimals: 18,
  },
  rpcUrls: {
    default: { http: ["https://arb1.arbitrum.io/rpc"] },
    public: { http: ["https://arb1.arbitrum.io/rpc"] },
  },
  blockExplorers: {
    default: {
      name: "arbiscan.io",
      url: "https://arbiscan.io",
    },
  },
})

wagmi read-only config

Read-only transport example generated from Main.net fields. It does not include account adapters or transaction actions.

import { createConfig, http } from 'wagmi'
import { arbitrumOneMainnet } from './arbitrum-one'

export const config = createConfig({
  chains: [arbitrumOneMainnet],
  transports: {
    [arbitrumOneMainnet.id]: http("https://arb1.arbitrum.io/rpc"),
  },
})

ethers read-only provider

Read-only JsonRpcProvider example generated from Main.net fields. It does not create a signer.

import { JsonRpcProvider } from 'ethers'

export const provider = new JsonRpcProvider("https://arb1.arbitrum.io/rpc", {
  chainId: 42161,
  name: "arbitrum-one",
})

const network = await provider.getNetwork()
console.log(network.chainId)

bash

curl eth_chainId check

Minimal JSON-RPC identity check. This verifies the endpoint-reported chain ID only, not uptime or production suitability.

curl -s -X POST \
  -H 'content-type: application/json' \
  --data '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}' \
  https://arb1.arbitrum.io/rpc

# Expected chain ID: 42161 / 0xa4b1

Developer signals

External dashboards a developer may inspect before choosing where to deploy. Main.net links to these references but does not collect the metric values, normalize methodologies, rank chains, or recommend deployments.

activitygrowthepie chain metricsExternal activity, cost, throughput, stablecoin, and ecosystem metrics where this chain is covered.liquidityDeFiLlama chain pageExternal TVL, stablecoin, volume, fee, and protocol coverage where this chain is covered.riskL2BEAT project pageExternal L2 risk, value secured, activity, data availability, and trust-assumption research where this chain is covered.explorerArbitrum One explorerExplorer-hosted blocks, transactions, contracts, token transfers, and verification tools from the listed explorer.

Main.net links to external developer-signal dashboards but does not collect, normalize, rank, or republish their metric values in this version.
External metrics can use different methodologies and update schedules. Check the linked provider documentation before comparing chains.
These links are not recommendations, rankings, investment advice, or claims that a chain is suitable for a specific application.

Source links

Arbitrum RPC endpoints

Safety note

Compare bridge routes, withdrawal timing, and finality assumptions before moving large balances across rollups.

Main.net is an independent reference site. It does not operate this chain, custody assets, execute transactions, or provide investment advice.

Report a correction

If this page has stale RPC, explorer, chain ID, or source information, open a public correction issue with a source link so it can be checked.

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