Free Optimism RPC Endpoint
Chain ID 10 · ETH · multiple configured routing regions
Optimism (Chain ID 10) is an OP-Stack rollup secured by Ethereum and home of the Superchain. NodeFlare runs dedicated Optimism nodes with multi-region routing and automatic failover.
Public endpoint — no API key
HTTPS
https://rpc.nodeflare.app/op/publicWSS
wss://rpc.nodeflare.app/op/ws/publicNeed higher limits? Use a keyed endpoint https://rpc.nodeflare.app/op/v1/{YOUR_KEY} — get a free key →
Connect to Optimism
curl -s -X POST https://rpc.nodeflare.app/op/public \
-H 'content-type: application/json' \
-d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'import { ethers } from "ethers";
const provider = new ethers.JsonRpcProvider(
"https://rpc.nodeflare.app/op/public"
);
const block = await provider.getBlockNumber();import { createPublicClient, http } from "viem";
const client = createPublicClient({
transport: http("https://rpc.nodeflare.app/op/public"),
});
const block = await client.getBlockNumber();from web3 import Web3
w3 = Web3(Web3.HTTPProvider(
"https://rpc.nodeflare.app/op/public"
))
print(w3.eth.block_number)Add Optimism to your wallet
Network details for MetaMask, Rabby, or any EVM wallet — Optimism chain ID 10 (0xa).
| Network name | Optimism |
| RPC URL | https://rpc.nodeflare.app/op/public |
| Chain ID | 10 |
| Currency symbol | ETH |
| Block explorer | https://optimistic.etherscan.io |
A wallet polls its RPC continuously. The keyless URL above allows 1 request per 10 seconds per IP: enough to confirm the network details, too low for daily wallet use. For a wallet, enter your keyed URL https://rpc.nodeflare.app/op/v1/{YOUR_KEY} instead. A free key allows 10 requests per second, and the dashboard adds Optimism to MetaMask with that URL in one click. Get a free key →
Built for Optimism
Superchain apps, low-cost DeFi, and onchain governance on Optimism. Requests use configured regional preferences and available upstreams. Plan rate limits, compute units and method-specific concurrency limits apply.
Optimism node coverage and routing
NodeFlare-operated primary nodes in 2 configured routing regions. A public third-party RPC backstop is configured after our own nodes. Region labels describe routing configuration rather than a guarantee that every gateway has a local node. A standard API key uses shared infrastructure with its own plan limits; dedicated capacity is scoped separately. Historical state, tracing and WebSocket support vary by chain and node.
On successful HTTP RPC responses, nf-region: fallback identifies an external backstop and nf-region: cache identifies a cached response. See our routing disclosure and availability terms.
Optimism RPC — FAQ
What is Optimism's chain ID?
Optimism's chain ID is 10 (hex 0xa). Its native currency is ETH and its block explorer is optimistic.etherscan.io. You can connect with NodeFlare's free public RPC at https://rpc.nodeflare.app/op/public — no API key required.
How do I add Optimism to MetaMask?
In MetaMask, open the network menu → "Add a network" → "Add a network manually", then enter — Network name: Optimism; Chain ID: 10; Currency symbol: ETH; Block explorer URL: https://optimistic.etherscan.io; New RPC URL: your keyed NodeFlare URL, https://rpc.nodeflare.app/op/v1/{YOUR_KEY}. A free key allows 10 requests per second. The keyless URL https://rpc.nodeflare.app/op/public answers a test call, but it allows 1 request per 10 seconds per IP, which is too low for a wallet that polls the network continuously.
What is the Optimism RPC URL?
NodeFlare's public Optimism RPC URL is https://rpc.nodeflare.app/op/public over HTTPS and wss://rpc.nodeflare.app/op/ws/public over WSS. No API key is required for the public endpoint.
Is the Optimism RPC free?
Yes. The public Optimism endpoint is free with no sign-up. A free API key provides higher rate limits and 3,000,000 compute units per month, no credit card. Heavy HTTP methods depend on node support and are subject to compute-unit and concurrency limits.
What are the Optimism RPC rate limits?
The public endpoint is limited to 1 request per 10 seconds per IP. A free key gives 10 requests/second; standard paid plans scale to 1500 req/s. Every plan includes all 17 supported chains.
Is NodeFlare a good Optimism RPC provider?
NodeFlare operates its own primary Optimism nodes. NodeFlare-operated primary nodes in 2 configured routing regions. A public third-party RPC backstop is configured after our own nodes. A free key provides 3,000,000 CU per month and higher limits. Method support and historical coverage depend on the node and requested block.
Is there a dedicated Optimism RPC node?
A standard key gives an authenticated endpoint on shared NodeFlare infrastructure, with plan-specific limits. Dedicated capacity is scoped separately by inquiry. NodeFlare-operated primary nodes in 2 configured routing regions. A public third-party RPC backstop is configured after our own nodes. Historical state and traces must be checked for your specific methods and block ranges; a key does not guarantee complete archive coverage.
Go deeper
- Full Optimism API reference → — supported methods, WebSocket, regions
- Rate limits & compute-unit costs → — what each method costs against your quota
- Pay per request with x402 → — Optimism calls in USDC from $0.001, no account:
POST /op/x402 - RPC for trading bots → and indexers → — low-latency, eth_getLogs-heavy workloads
- Screen a Optimism token for scams → — ownership, honeypot check, holder concentration → one risk score
- Compare Optimism gas prices → — live gas price and transaction cost next to the other chains, and a free token approval checker →
- Onchain tools for AI agents → — token-safety, wallet intelligence and RPC over MCP / x402
Build on Optimism with a free key
Higher limits and an authenticated endpoint — every supported chain included. No credit card.
Get your free API key →Optimism RPC methods
Per-method docs for Optimism — parameters, compute-unit cost, and copy-paste examples.