Hyperliquid Mainnet vs Testnet
Hyperliquid mainnet carries real assets and production market state, while testnet is the safer environment for integration work, contract testing, and API experiments.
Hyperliquid mainnet and testnet expose similar concepts but should be treated as different environments with different chain IDs, endpoints, assets, and economic consequences. Mainnet is production. Testnet exists so developers and users can validate transactions, signing, smart contracts, and market workflows without treating test assets as real capital.
Chain and endpoint separation
HyperEVM mainnet uses chain ID 999 and testnet uses chain ID 998 according to the developer documentation. API and WebSocket endpoints are also environment-specific.
Hard-coding an endpoint without an explicit environment setting is a common integration mistake. A robust application makes network selection visible and refuses to sign mainnet actions when running in a test configuration.
What testnet is good for
Testnet is useful for validating signing, nonce handling, API-wallet permissions, order flows, WebSocket reconnect behavior, contract deployment, CoreWriter encoding, and frontend state handling.
It is also where developers should deliberately simulate failures: dropped connections, stale data, insufficient margin, rejected orders, invalid nonces, and unsupported actions.
What testnet cannot prove
A test environment does not reproduce real liquidity, volatility, market-maker competition, production rate-limit behavior under load, or the economic incentives of mainnet. Successful execution on testnet therefore proves functional compatibility, not production trading performance.
A strategy that appears profitable against shallow or artificial test liquidity should not be treated as evidence of mainnet profitability.
Production checklist
Before moving to mainnet, separate keys and API wallets, enforce notional limits, verify the correct chain ID and URLs, add monitoring, implement retries that cannot duplicate unsafe actions, and make environment state obvious in logs and interfaces.
For contracts, confirm deployment addresses and dependencies independently. For trading systems, start with deliberately small notional and validate fills, positions, fees, and reconciliation before increasing exposure.