What is an Ethereum RPC node and how do I choose one?

Ethereum RPC Node decision checklist

Before selecting an Ethereum RPC node, consider these factors:

• Throughput requirements: Estimate your peak requests per second (RPS). Shared nodes may throttle at high volumes; dedicated nodes provide consistent capacity.
• Reliability needs: For production apps, look for providers with redundant infrastructure and SLAs. Avoid single points of failure.
• Data access: Full nodes provide current state; archive nodes store historical data. If you need past block states or trace calls, choose an archive node.
• Geographic distribution: Low latency requires nodes close to your users. Providers with global endpoints reduce round-trip time.
• Security and privacy: Shared nodes may log requests. Dedicated nodes offer isolation and better control over data.
• Cost model: Evaluate free tiers, pay-as-you-go, and flat-rate plans. Factor in overage charges for burst traffic.
• Testnet support: Ensure the provider offers Sepolia or Holesky endpoints for development and testing.

What is an Ethereum RPC node?

An Ethereum RPC node is a server that runs an Ethereum client (e.g., Geth, Nethermind, Erigon) and exposes the JSON-RPC API. This API allows external applications—wallets, dApps, block explorers—to read blockchain data (balances, transaction receipts, logs) and submit transactions. The term "RPC" stands for Remote Procedure Call, a protocol that lets a program request a service from another program on a different machine.

Every Ethereum node implements the same JSON-RPC specification, so you can use the same API methods regardless of the client software. Common methods include eth_blockNumber, eth_getBalance, eth_sendRawTransaction, and eth_call. The API is transport-agnostic but typically accessed over HTTP or WebSocket.

How does JSON-RPC work?

JSON-RPC is a lightweight protocol that uses JSON for data encoding. A request contains a method name, parameters, and an ID. The node responds with a result or error. Here's a simple example using curl to get the latest block number:

curl -X POST https://eth.drpc.org \
  -H "Content-Type: application/json" \
  --data '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

Response:

{"jsonrpc":"2.0","id":1,"result":"0x134e2a0"}

The result is hex-encoded. To use it in JavaScript with ethers.js:

const { ethers } = require("ethers");
const provider = new ethers.JsonRpcProvider("https://eth.drpc.org");
provider.getBlockNumber().then(console.log);

Types of Ethereum RPC nodes

Full nodes

A full node stores the entire blockchain and validates all blocks. It can serve current state data but prunes historical state older than a certain number of blocks (e.g., 128 blocks for Geth). Full nodes are sufficient for most dApps that need recent data.

Archive nodes

Archive nodes retain all historical state, allowing queries like eth_getBalance at any past block. They require significantly more storage (multiple TB) and are used by block explorers, analytics platforms, and services that need deep history.

Shared vs. dedicated nodes

• Shared nodes: Multiple users share the same node infrastructure. Providers rate-limit requests to ensure fairness. Suitable for development, low-traffic apps, and testing.
• Dedicated nodes: You get a private node with guaranteed resources. clear rate limitsing from other tenants, better performance consistency, and full control over the client configuration.

How to choose an Ethereum RPC provider

When evaluating providers, compare these criteria:

Setting up your own Ethereum RPC node

Running your own node gives you full control but requires technical expertise and infrastructure. Here's a minimal setup using Geth:

1. Install Geth on a Linux server (recommended: Ubuntu 22.04+).
2. Start the node with HTTP RPC enabled:

geth --syncmode snap --http --http.addr 0.0.0.0 --http.port 8545 --http.api eth,net,web3

3. The RPC endpoint will be http://<your-server-ip>:8545.

Important considerations:

• Initial sync can take days and requires ~1TB of storage for a full node.
• You must keep the node updated and monitor its health.
• Security: restrict access via firewall and use TLS if exposed to the internet.

For most teams, using a managed RPC service is more practical. OnFinality offers both shared and dedicated Ethereum RPC nodes with global endpoints, archive support, and flexible pricing. Check our supported RPC networks and RPC pricing for details.

Common pitfalls and troubleshooting

• Rate limiting: If you receive HTTP 429 errors, you've exceeded the provider's rate limit. Upgrade to a higher tier or use a dedicated node.
• Nonce errors: When sending transactions, ensure the nonce is correct. Use eth_getTransactionCount with the pending block parameter.
• Block not found: If querying a recent block, it may not yet be finalized. Use the latest or safe block tag as appropriate.
• WebSocket disconnections: For real-time feeds, implement reconnection logic in your client.

Key Takeaways

• An Ethereum RPC node is the gateway for applications to interact with the blockchain.
• Choose between full and archive nodes based on your data needs.
• Shared nodes are cost-effective for low traffic; dedicated nodes offer consistent performance.
• Evaluate providers on throughput, latency, uptime, and pricing.
• Managed services simplify operations; OnFinality provides reliable Ethereum RPC endpoints for mainnet and testnets.

Frequently Asked Questions

What is the difference between an Ethereum node and an RPC node? An Ethereum node is the software that runs the blockchain protocol. An RPC node is a node that exposes the JSON-RPC API, allowing external applications to interact with it.

Can I use a free Ethereum RPC node for production? Free tiers are suitable for development and low-traffic apps. For production, consider a paid plan with guaranteed throughput and uptime.

How do I find the best Ethereum RPC endpoint? Compare providers based on latency, reliability, and features. Services like OnFinality offer multiple endpoints with automatic failover.

What is an archive node? An archive node stores the complete history of the Ethereum blockchain, enabling queries for any past state. It requires significant storage.

How do I switch RPC providers? Update the RPC URL in your application configuration. If using a library like ethers.js, change the provider URL and test thoroughly.

For more details, visit our Ethereum RPC API service or explore all supported networks.