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Sei uses multiple chains for different stages of the development lifecycle. With this multi-chain approach, you can build, deploy, manage, and iterate with confidence. Updates also get thorough testing and feedback before they go live on Sei Mainnet.
Every chain update goes to Sei Testnet first for thorough testing and validation. After that, the update is released to Sei Mainnet. This lets you test your dApps thoroughly and raise any concerns about an update before it goes live on Sei Mainnet.

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Mainnet

Sei Mainnet is the live production environment, where real transactions and smart contract deployments happen. All real-world dApps and activities use this chain.
  • Purpose: Production
  • Cosmos chain ID: pacific-1
  • EVM chain ID: 1329 or 0x531
  • EVM RPC: https://evm-rpc.sei-apis.com
  • WebSocket: wss://evm-ws.sei-apis.com
  • Explorer: https://seiscan.io

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Testnet

Sei Testnet is for testing and development. You can deploy and test your dApps and smart contracts in a controlled environment that simulates Sei Mainnet conditions. Use this chain to make sure that your dApps work as expected before they go live.
  • Purpose: Staging
  • Cosmos chain ID: atlantic-2
  • EVM chain ID: 1328 or 0x530
  • EVM RPC: https://evm-rpc-testnet.sei-apis.com
  • WebSocket: wss://evm-ws-testnet.sei-apis.com
  • Explorer: https://testnet.seiscan.io

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Local chains

You can also run local chains on your machine for testing and development. Local chains are isolated environments that mimic the behavior of Sei Mainnet or Sei Testnet. On a local chain, you have full control over all tokens and governance decisions. This makes local chains useful for testing new features, debugging issues, and experimenting with smart contracts.
  • Purpose: Development
  • Cosmos chain ID: Set by you (default: sei-chain)
To learn how to set up and run a local chain, read the Nodes Introduction section.
For more chain-specific information, RPC endpoints, and explorers, see Sei EVM networks.

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Chain registry

The Sei Chain Registry has more information about each chain.