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What is a testnet?
A testnet is a separate copy of a blockchain network used to try out software and smart contracts before they go live. Its coins are handed out free by websites called faucets and are meant to have no real value.
What it means for you
Testnet coins exist only on the testnet and cannot be spent on mainnet. They are meant to be free from faucets, so paying real money for them buys nothing on mainnet, and a wallet switched to a testnet shows balances that are not mainnet funds; check the network name.
A common mistake: “Testnet coins I bought can be moved to mainnet.”
In fact: They cannot. A testnet is a separate chain whose balances do not carry over, and its coins are meant to be handed out free by faucets with no real value.
How it works
A testnet runs the same kind of software as mainnet but keeps a separate chain, so balances and history do not carry over between them. ethereum.org lists a default testnet for application development with a permissioned validator set, one with an open validator set for stakers testing upgrades before mainnet, and one that resets to genesis every 28 days. Layer 2 networks run testnets paired with these. Test ETH comes from faucets and is supposed to have no value, though markets have occasionally formed for scarce testnet tokens.
Source: ethereum.org: Networks · checked 4 October 2026
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Educational content, not financial advice. Written by hand and checked against the source named above. Something wrong? Tell us and we reply within two business days.