Arbitrum RPC List: How to Choose the Right Endpoint for Your App

When you search for an "Arbitrum RPC list," you're likely looking for a reliable endpoint to connect your dApp, wallet, or bot to Arbitrum One. The right RPC can mean the difference between smooth transactions and frustrating timeouts. This guide breaks down the types of RPCs available, how to choose one, and how to configure it.

Quick Recommendation: Which Arbitrum RPC Should You Use?

For production applications, a managed or dedicated RPC provider is almost always the right choice over a public endpoint. Public RPCs are fine for testing and light usage, but they often have rate limits and can be unreliable under load. If you're building a serious dApp, you need consistent performance and support.

• For development and testing: Use a public Arbitrum RPC or a free tier from a provider.
• For production dApps: Choose a managed RPC provider that offers scalability, monitoring, and support.
• For high-throughput or data-intensive applications: Consider a dedicated node to avoid shared resource contention.

OnFinality offers managed and dedicated Arbitrum RPC endpoints that are designed for production workloads. You can explore the Arbitrum network page for more details.

Understanding Arbitrum RPC Endpoints

Arbitrum is an Ethereum Layer 2 scaling solution that uses optimistic rollups. To interact with Arbitrum, your application sends JSON-RPC requests to an RPC endpoint, just like on Ethereum. The main network is Arbitrum One, with chain ID 42161. There is also a testnet, Arbitrum Sepolia, with chain ID 421614.

Here are the key chain settings for Arbitrum One:

For Arbitrum Sepolia:

These public endpoints are a good starting point for development. However, they are shared and may have rate limits. For production, you'll want a private endpoint.

Types of Arbitrum RPC Providers

When you look for an Arbitrum RPC list, you'll encounter three main types of providers:

1. Public RPCs: Free, open endpoints provided by the community or projects. They are often rate-limited and not suitable for production.
2. Managed RPC Providers: Services like OnFinality that offer reliable, scalable RPC endpoints with API keys, monitoring, and support. They typically have free tiers and paid plans.
3. Dedicated Nodes: You get a dedicated node instance, giving you full control over resources and no sharing. This is ideal for high-traffic applications.

Public RPCs

Public RPCs are convenient for quick tests and prototypes. However, they can be slow, unreliable, and may block certain requests. They are not recommended for production apps.

Managed RPC Providers

Managed providers handle the infrastructure for you. They offer load balancing, failover, and multiple endpoints to ensure high availability. OnFinality, for example, provides a global network of nodes and a simple API key system.

Dedicated Nodes

With a dedicated node, you get a single-tenant instance. This means no noisy neighbors and consistent performance. It's the best choice for applications with heavy usage or specific requirements like archive data.

How to Choose an Arbitrum RPC Provider

Choosing the right provider depends on your needs. Here are key factors to evaluate:

• Reliability: Look for providers with a track record of uptime and low latency.
• Scalability: Can the provider handle spikes in traffic?
• Support: Do they offer responsive customer support?
• Features: Do they support WebSocket connections, archive data, or trace methods?
• Pricing: Compare plans and see if they fit your budget.

OnFinality offers a range of plans, including a free tier, and you can view the RPC pricing page for details. We also support a wide range of networks, as you can see on our supported networks page.

Setting Up Your Arbitrum RPC Connection

Once you've chosen an endpoint, you need to configure your application. Here's an example using ethers.js in JavaScript:

const { ethers } = require("ethers");

const provider = new ethers.JsonRpcProvider("https://arbitrum.api.onfinality.io/public");

async function getBlockNumber() {
  const blockNumber = await provider.getBlockNumber();
  console.log("Current block number:", blockNumber);
}

getBlockNumber();

If you're using a managed provider, you'll typically get an API key and use a URL like https://arbitrum.api.onfinality.io/v1/your-api-key.

For wallets, you can add Arbitrum One as a custom network:

{
  "chainId": "0xA4B1",
  "chainName": "Arbitrum One",
  "nativeCurrency": {
    "name": "Ether",
    "symbol": "ETH",
    "decimals": 18
  },
  "rpcUrls": ["https://arbitrum.api.onfinality.io/public"],
  "blockExplorerUrls": ["https://arbiscan.io"]
}

Note that the chain ID 0xA4B1 is the hexadecimal representation of 42161.

Common Use Cases for Arbitrum RPC

Arbitrum RPCs are used for a variety of purposes:

• DeFi applications: Interacting with smart contracts, reading balances, and sending transactions.
• NFT marketplaces: Fetching token metadata and transaction history.
• Analytics tools: Indexing blockchain data.
• Bots and automation: Monitoring events and executing trades.

Each use case has different requirements. For example, a trading bot needs low latency, while an analytics platform might need archive data.

Troubleshooting Common RPC Issues

Even with a good provider, you might encounter issues. Here are common problems and solutions:

• Rate limiting: If you're hitting rate limits, consider upgrading your plan or using a dedicated node.
• Connection timeouts: This could be due to network issues or an overloaded endpoint. Try a different endpoint or increase your timeout settings.
• Incorrect chain ID: Make sure your application is using the correct chain ID (42161 for Arbitrum One).
• WebSocket disconnections: If you're using WebSocket, implement reconnection logic.

For more detailed troubleshooting, you can refer to our guide on RPC troubleshooting (though that's more about provider selection, the principles apply).

Key Takeaways

• Arbitrum One has chain ID 42161 and uses ETH as its native currency.
• Public RPCs are fine for development, but production apps should use managed or dedicated RPCs.
• When choosing a provider, consider reliability, scalability, support, and pricing.
• OnFinality offers managed and dedicated Arbitrum RPC endpoints with a free tier.
• Always use the correct chain ID and network settings in your application.

Frequently Asked Questions

What is the official Arbitrum RPC endpoint?

There is no single official endpoint, but the Arbitrum team provides public RPCs. OnFinality also offers a public endpoint at https://arbitrum.api.onfinality.io/public.

What is the difference between Arbitrum One and Arbitrum Nova?

Arbitrum One is the main rollup for general DeFi and dApps, while Arbitrum Nova is optimized for gaming and social apps. This article focuses on Arbitrum One.

Can I use the same RPC for Arbitrum Sepolia?

No, you need a separate endpoint for the testnet. OnFinality provides a public endpoint for Arbitrum Sepolia at https://arbitrum-sepolia.api.onfinality.io/public.

How do I get a private Arbitrum RPC?

You can sign up for a managed RPC provider like OnFinality and get a private endpoint with an API key. Visit our pricing page for more details.

What is the chain ID for Arbitrum?

The chain ID for Arbitrum One is 42161. For Arbitrum Sepolia, it's 421614.

Does OnFinality support WebSocket for Arbitrum?

Yes, OnFinality supports WebSocket connections for Arbitrum. You can find the WebSocket URL in your dashboard after creating an API key.

How can I monitor my Arbitrum RPC usage?

Most managed providers offer usage analytics. OnFinality provides a dashboard where you can monitor your requests and usage.

What is an archive node and do I need one?

An archive node stores the full historical state of the blockchain. If your application needs to query historical data at any point in time, you'll need an archive node. OnFinality offers archive node options for Arbitrum.

Can I use a free RPC for production?

It's not recommended. Free RPCs often have rate limits and no uptime guarantees. For production, invest in a reliable provider.

How do I switch from a public RPC to a managed one?

Simply update the RPC URL in your application configuration. If you're using a library like ethers.js, you just change the provider URL. Make sure to test thoroughly after switching.