opBNB RPC Endpoint

Flat-rate opBNB RPC provider and opBNB RPC node access: free tier, no KYC, HTTP & WebSocket. opBNB mainnet chain ID 204.

opBNB is a Layer 2 scaling network for BNB Smart Chain built on the Optimism OP Stack (Bedrock). It uses BNB as its gas token and is tuned for high throughput and low fees.

About opBNB

opBNB was developed by the BNB Chain team and launched its mainnet in 2023 as an optimistic rollup that settles to BNB Smart Chain. It is built on the OP Stack with optimizations aimed at higher gas limits and throughput than a default OP Stack deployment.

The network is EVM-compatible and uses BNB for gas, so standard Ethereum tooling such as Hardhat, Foundry, ethers.js, and viem applies directly. opBNB produces a block roughly every 0.25 seconds (measured September 2026) with very low transaction fees, making it suited to gaming, social, and high-frequency dApps. As an optimistic rollup it carries a 7-day challenge window for withdrawals back to BNB Smart Chain.

Common Use Cases on opBNB

• Low-fee EVM transactions
• On-chain gaming
• SocialFi applications
• High-frequency dApps
• DeFi protocols
• NFT minting

opBNB Ecosystem

opBNB hosts DeFi and infrastructure projects within the BNB Chain ecosystem, including deployments from PancakeSwap and tooling from providers such as Pyth and the BNB Greenfield stack.

opBNB Mainnet RPC URL (HTTP)

opBNB WebSocket RPC URL

Quick Start: Connect to opBNB

cURL

curl -X POST https://rpc.swiftnodes.io/rpc/opbnb?key=YOUR_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'

ethers.js

import { JsonRpcProvider } from "ethers";

const provider = new JsonRpcProvider(
  "https://rpc.swiftnodes.io/rpc/opbnb?key=YOUR_API_KEY"
);

const blockNumber = await provider.getBlockNumber();
console.log("opBNB block:", blockNumber);

viem

import { createPublicClient, http } from "viem";

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

const blockNumber = await client.getBlockNumber();

web3.py

from web3 import Web3

w3 = Web3(Web3.HTTPProvider("https://rpc.swiftnodes.io/rpc/opbnb?key=YOUR_API_KEY"))
print("opBNB block:", w3.eth.block_number)

Add opBNB to MetaMask

Bridging to opBNB

Assets bridge through the opBNB canonical bridge from BNB Smart Chain, with additional routes via Celer cBridge and other third-party bridges.

Features of SwiftNodes for opBNB

• Load-balanced across multiple upstream nodes wherever a chain has more than one, with automatic failover
• Health-checked every 2 minutes with automatic failover
• Free tier available — no credit card or KYC required
• Flat-rate monthly pricing with no per-request fees
• HTTP and WebSocket support
• One API key works across all 75+ supported chains, including opBNB

Rate Limits

Frequently Asked Questions: opBNB

opBNB guides from the blog

• opBNB RPC: A Developer's Guide (Chain ID 204)opBNB is an OP Stack L2 settling to BNB Smart Chain, with 250 ms blocks. Measured finality, fees, the 50,000-block getLogs cap and a stale-finality trap.
• Optimism RPC: The Chain That Became a TemplateOptimism (chain ID 10) is both a mature optimistic rollup — 2-second blocks, ETH gas, fault proofs live since 2024 — and the origin of the OP Stack, the codebase behind Base, Zora, opBNB, Unichain, and Soneium. The developer map: what the two-layer fee model means for gas estimation, why traces are uneven there, and how everything you learn on OP Mainnet carries across the family.

Related L2 & rollup chains

Explore RPC endpoints for other L2 & rollup networks on SwiftNodes: