Testnet vs mainnet address identifiers
Ethereum testnet and mainnet use the same address shape. Account balances, deployed contracts and transaction histories belong to separate networks.
Worked example
| Context | Address shape | Separate state |
|---|---|---|
| Ethereum mainnet | 0x + 40 hex | Real mainnet account and contract state |
| Ethereum testnet | 0x + 40 hex | Test balances and deployments |
| Solana clusters | Same account encoding | Mainnet, devnet and testnet data |
Worked contract lookup
A tutorial deploys an NFT on a test network. Searching that contract address on the mainnet explorer may show no code or an unrelated deployment. Keep the tutorial’s network label beside the contract and token ID.
Test examples stay test examples
A faucet or test token demonstrates behavior in a test environment; it is not a mainnet asset mapping. Conversely, a documented EIP-55 address fixture tests text handling and does not establish an account exists on any network.
Common pitfalls
- Changing the wallet’s network does not move assets between chains.
- Never use a mainnet payment to test a placeholder from a tutorial.
Related references
Primary sources
Examples explain identifiers. They are not investment recommendations.