How can developers test new subnets locally?

• A. Use testnets or local simulators with mock AVAX tokens to simulate subnet deployment and VM behavior.
• B. Run on mainnet with real AVAX tokens.
• C. Use testnets only on the P-Chain.
• D. Testing is not supported for subnets.

Answer: (A)

Testing a new subnet locally is done by using public testnets or local simulators that mimic the Avalanche environment, paired with mock AVAX tokens to simulate deployment and VM execution. This setup lets you verify how the subnet would be deployed, how the validator set operates, and how the custom VM will run transactions, manage gas, and handle errors—without risking real funds. It provides a safe, repeatable space to iterate on configuration, governance hooks, and VM logic before any mainnet rollout. Running on the mainnet with real AVAX would expose assets to cost and risk, and network conditions can be unpredictable. Testing on the P-Chain alone wouldn’t exercise the subnet’s execution environment in the same way, since the P-Chain handles subnet governance rather than running the subnet’s VM. And testing support exists, so using testnets or local simulators is the intended approach.