This document is reference for the networks I use regularly, and is usually up to date. If something doesn't work, you should use ChainList. You can convert chainIds to hex using tools like eserialize to do so.
Example: Convert Polygon Mumbai chainId
Mainnets
| Network | RPC URL | Chain | Hex | Symb | Explorer URL |
|---|---|---|---|---|---|
| Mainnet | eth.llamarpc.com | 1 | 0x1 | ETH | etherscan.io |
| Polygon | polygon-rpc.com | 137 | 0x89 | MATIC | polygonscan.com |
| Optimism | mainnet.optimism.io | 10 | 0xa | ETH | optimistic.etherscan.io |
Testnets
| Network | RPC URL | Chain | Hex | Symb | Explorer URL |
|---|---|---|---|---|---|
| Mumbai | rpc-mumbai.maticvigil.com | 80001 | 0x13881 | MATIC | mumbai.polygonscan.com |
| Goerli | goerli.blockpi.network | 5 | 0x5 | ETH | goerli.etherscan.io |