RPC method

eth_estimateGas on opBNB

Supported on SwiftNodes

Everything below was measured on 2026-10-13 by calling eth_estimateGas on opBNB through the same endpoint customers use, and is re-measured weekly.

What eth_estimateGas does

Runs a transaction against current state and returns the gas it would use, so you can set a gas limit. If the transaction would revert or the sender cannot pay, the node returns an error instead of a number.

eth_estimateGas on opBNB: what we measured

Zero-value BNB transfer to an EOA	21,000 gas
Same on Ethereum	21,000 gas
1 wei from an empty account	err: insufficient funds for gas * price + value: address 0x758FAcc4A8895022cFA5933b5c8ce782B019C832 have 0 want 1 (supplied gas 50010499)

What the numbers mean

A plain transfer estimates at exactly 21,000 gas on opBNB, as on Ethereum. Contract calls vary with state, so estimate those rather than hard-coding a limit.

An estimate for a sender that cannot pay fails with: "err: insufficient funds for gas * price + value: address 0x758FAcc4A8895022cFA5933b5c8ce782B019C832 have 0 want 1 (supplied gas 50010499)". Your app sees this text when a user's balance is too low, so match on it to show a clear message.

Chains where a transfer is not 21,000 gas

Of the 53 chains we measure, 6 estimate a plain transfer at something other than 21,000 gas.

Example request

curl -s https://rpc.swiftnodes.io/rpc/opbnb?key=YOUR_API_KEY \
  -X POST -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_estimateGas","params":[{"from":"0x0000000000000000000000000000000000000000","to":"0x000000000000000000000000000000000000dEaD","value":"0x0"}]}'

import { createPublicClient, http } from "viem";

const client = createPublicClient({
  transport: http("https://rpc.swiftnodes.io/rpc/opbnb?key=YOUR_API_KEY"),
});

const gas = await client.estimateGas({ account: from, to, value });
// Add headroom: state can change between estimate and inclusion
const gasLimit = (gas * 120n) / 100n;

Other methods on opBNB

eth_estimateGas on other chains

Frequently asked questions

Does opBNB support eth_estimateGas?

Yes. eth_estimateGas answered on the SwiftNodes opBNB endpoint when our weekly probe called it through the customer path (2026-10-13).

How much gas does a plain transfer use on opBNB?

eth_estimateGas returned 21,000 for a plain transfer on 2026-10-13.

What does "insufficient funds for gas * price + value" mean from eth_estimateGas on opBNB?

The sender's balance cannot cover the value plus the gas. Fund the account or lower the value; the have and want figures in the message are in wei.

opBNB endpoints, live block height and WebSocket status are on the opBNB RPC page.

One key covers every chain we serve, and SwiftNodes has a free tier.