Optimism Documentation

This page provides network information for OP Mainnet and OP Sepolia, including RPC endpoints, chain IDs, and block explorers.

The public RPC URLs provided below are rate limited and do not support websocket connections. If you are experiencing rate limiting issues or need websocket functionality, consider running your own node or signing up for a third-party RPC provider.

OP Mainnet

Parameter	Value
Network Name	`OP Mainnet`
Chain ID	`10`
Currency Symbol¹	ETH
Explorer	https://explorer.optimism.io
Public RPC URL	https://mainnet.optimism.io
Sequencer URL²	https://mainnet-sequencer.optimism.io
Flashblocks websocket URL ³	wss://op-mainnet-fb-ws-pub.optimism.io/ws
Contract Addresses	Refer to the Contract Addresses page
Connect Wallet	Click here to connect your wallet to OP Mainnet

The “currency symbol” is required by some wallets like MetaMask.
The sequencer URL is write only.
Strictly rate-limited public URL. Please rely on Ethereum JSON RPC or reach out to the Optimism team for a more relaxed private endpoint.

OP Sepolia

Parameter	Value
Network Name	`OP Sepolia`
Chain ID	`11155420`
Currency Symbol¹	ETH
Explorer	https://testnet-explorer.optimism.io
Public RPC URL	https://sepolia.optimism.io
Flashblocks websocket URL ³	wss://op-sepolia-fb-ws.optimism.io/ws
Sequencer URL²	https://sepolia-sequencer.optimism.io
Contract Addresses	Refer to the Contract Addresses page
Connect Wallet	Click here to connect your wallet to OP Sepolia

The “currency symbol” is required by some wallets like MetaMask.
The sequencer URL is write only.
Strictly rate-limited public URL. Please rely on Ethereum JSON RPC or reach out to the Optimism team for a more relaxed private endpoint.

OP Mainnet Contract Addresses

⌘I

​OP Mainnet

​OP Sepolia

OP Mainnet

OP Sepolia