Skip to main content

Chain ID

A chain ID is a unique identifier that represents a blockchain network. We use it to distinguish different blockchain networks from each other and to ensure that transactions and messages are sent to the correct network. Evmos network follows the format of identifier_EIP155-version format.

Official Chain IDs


NOTE: The latest Chain ID (i.e highest Version Number) is the latest version of the software and mainnet. Also note, that the following upgrades technically did not require a Chain ID change:

  • evmos_9001-1 -> evmos_9001-2
  • evmos_9000-3 -> evmos_9000-4


NameChain IDIdentifierEIP155 NumberVersion NumberActive
Evmos 2evmos_9001-2evmos90012
Evmos 1evmos_9001-1evmos90011🚫


NameChain IDIdentifierEIP155 NumberVersion NumberActive
Evmos Public Testnetevmos_9000-4evmos90004
Evmos Public Testnetevmos_9000-3evmos90003🚫
Olympus Mons Incentivized Testnetevmos_9000-2evmos90002🚫
Arsia Mons Testnetevmos_9000-1evmos90001🚫

You can also lookup the EIP155 Chain ID by referring to website

The Chain Identifier

Every chain must have a unique identifier or chain-id. Tendermint requires each application to define its own chain-id in the genesis.json fields. However, in order to comply with both EIP155 and Cosmos standard for chain upgrades, Evmos-compatible chains must implement a special structure for their chain identifiers.


The Evmos Chain ID contains 3 main components

  • Identifier: Unstructured string that defines the name of the application.
  • EIP155 Number: Immutable EIP155 CHAIN_ID that defines the replay attack protection number.
  • Version Number: Is the version number (always positive) that the chain is currently running. This number MUST be incremented every time the chain is upgraded or forked in order to avoid network or consensus errors.


The format for specifying and Evmos compatible chain-id in genesis is the following:


The following table provides an example where the second row corresponds to an upgrade from the first one:

ChainIDIdentifierEIP155 NumberVersion Number