# IoTeX Chain ID

A Chain ID is a unique number assigned to different, independent IoTeX Blockchains. For example, IoTeX Mainnet chain has Chain ID = 1, while IoTeX Testnet has Chain ID = 2. Chain IDs in IoTeX are used for security reasons, by including it into transaction signature to prevent transaction replay attacks on different networks.

# List of IoTeX Chain ID's

All IoTeX-based blockchains should adopt this Chain ID Mechanism, but replacing CHAIN ID with a different and unique value. All testnet, consortium and IoTeX-cloned chains are encouraged to do the same:

1 IoTeX Mainnet
2 IoTeX Testnet