Testnet vs mainnet

A mainnet is a blockchain's live production network, where transactions are real and coins have value. A testnet is a separate copy of the network used by developers to test software, smart contracts and upgrades without risking real money.

Testnet coins are free and worthless by design. Developers get them from "faucets", websites that give out small amounts. Bitcoin has testnet and signet networks, and Ethereum's main public testnet is Sepolia. Major Ethereum upgrades are run on testnets for weeks before they reach mainnet.

For ordinary users, testnets matter in two ways. Some projects reward people who try their testnet before launch, which has led to "testnet farming" in the hope of an airdrop. And scammers sometimes sell testnet tokens or fake "mainnet swap" services. Never pay for testnet coins, and when a project announces a mainnet launch, use only links from its official channels.