Accounts & state2 CU

eth_getBalance on Optimism

Returns the native-token balance (in wei) of an address at a given block. The standard way to read a wallet's balance.

This returns the native coin only — for ERC-20 balances use eth_call against the token's balanceOf. Pass an explicit block number for point-in-time reads; latest moves every block.

Optimism endpoint (public — no key)

https://rpc.nodeflare.app/op/public

Method

eth_getBalance

Cost

2 CU

Chain ID

10

Block time

~2 s

Finality

~2 s soft · L1-final ~13 min

Accounts & state on Optimism

State reads behave as on Ethereum. The regenesis history (pre-Bedrock, Nov 2021–Jun 2023) means very old state may not be reachable the way recent state is.

Parameters

[address, blockNumber|tag]

cURL

curl https://rpc.nodeflare.app/op/public \
  -X POST \
  -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","method":"eth_getBalance","params":["0x0b2c639c533813f4aa9d7837caf62653d097ff85", "latest"],"id":1}'

The example targets the USDC contract on Optimism — you can run it as-is.

ethers.js

import { ethers } from 'ethers';

const provider = new ethers.JsonRpcProvider(
  'https://rpc.nodeflare.app/op/public'
);

const result = await provider.send('eth_getBalance', ["0x0b2c639c533813f4aa9d7837caf62653d097ff85", "latest"]);

Try it live

Runs the example above against the public Optimism endpoint — straight from your browser.

eth_getBalance on Optimism — FAQ

How do I call eth_getBalance on Optimism?

POST a JSON-RPC 2.0 request with "method": "eth_getBalance" to NodeFlare's Optimism endpoint at https://rpc.nodeflare.app/op/public. No API key is required for the public endpoint.

What does eth_getBalance cost on the free tier?

eth_getBalance is weighted at 2 compute units per call. The free tier includes 2,000,000 CU/month, so that is roughly 1,000,000 eth_getBalance calls per month — no credit card.

Is eth_getBalance available on the public Optimism endpoint?

Yes. eth_getBalance works on the public Optimism endpoint (https://rpc.nodeflare.app/op/public) with no API key, rate-limited per IP. A free key adds higher limits and a dedicated path.

Anything Optimism-specific to know when using eth_getBalance?

State reads behave as on Ethereum. The regenesis history (pre-Bedrock, Nov 2021–Jun 2023) means very old state may not be reachable the way recent state is.

Call eth_getBalance on Optimism with a free key

2,000,000 compute units/month, heavy methods unlocked, every chain included. No credit card.

Get your free API key →