[Supanode](https://supanode.xyz/)[Learn](https://supanode.xyz/learn)Chain ID and network ID answer different questions

# Chain ID and network ID answer different questions

Validate the chain used for EVM signing rather than relying on a network label.

**On this page**[Use chain identity in the signing path](https://supanode.xyz/learn/chain-id-vs-network-id#use-chain-identity-in-the-signing-path)[Check before a state-changing action](https://supanode.xyz/learn/chain-id-vs-network-id#check-before-a-state-changing-action)[Keep configuration atomic](https://supanode.xyz/learn/chain-id-vs-network-id#keep-configuration-atomic)[Robinhood example](https://supanode.xyz/learn/chain-id-vs-network-id#robinhood-example)[Sources](https://supanode.xyz/learn/chain-id-vs-network-id#sources)

## Use chain identity in the signing path

`eth_chainId` reports the chain identifier used by EVM transaction signing. `net_version` reports a network identifier. They may coincide, but applications should not assume they are interchangeable or use the latter to override a configured signing chain.

## Check before a state-changing action

```
[{"jsonrpc":"2.0","id":"chain","method":"eth_chainId","params":[]},{"jsonrpc":"2.0","id":"network","method":"net_version","params":[]}]
```

The chain result is a hexadecimal quantity, while net\_version is normally a decimal string. Convert both explicitly before displaying them. Never compare the raw strings as if different formatting proved a network mismatch.

## Keep configuration atomic

1.  Store chain ID, RPC endpoint and explorer together in a named network configuration.
2.  At startup, query eth\_chainId and compare it with the expected value. Fail closed when they differ.
3.  Repeat the check when a user changes wallets or an operator changes endpoints.
4.  Keep testnet credentials, deployment addresses and transaction journals separate from mainnet.

## Robinhood example

Robinhood publishes mainnet chain ID 4663 and testnet chain ID 46630. The corresponding hexadecimal values are `0x1237` and `0xb626`. These identifiers do not tell you whether a particular token address or contract deployment exists on both networks. Read code and verify deployment metadata on the intended chain before preparing transactions.

## Sources

-   [Ethereum JSON-RPC](https://ethereum.org/en/developers/docs/apis/json-rpc/)
-   [EIP-155](https://eips.ethereum.org/EIPS/eip-155)
-   [EIP-1474](https://eips.ethereum.org/EIPS/eip-1474)
-   [Robinhood connection parameters](https://docs.robinhood.com/chain/connecting/)

## Continue reading

[Robinhood RPC and WebSocket](https://supanode.xyz/blog/robinhood-chain-rpc-websocket)[Robinhood methods](https://supanode.xyz/docs/robinhood/rpc/whats-available)[Learn library](https://supanode.xyz/learn)

---
Source: https://supanode.xyz/learn/chain-id-vs-network-id