Testnet

A testnet (test network) is a parallel version of a blockchain used for development and testing. Its coins are free and carry no real value, so mistakes are harmless.

How it works

A testnet mirrors how the real network (the mainnet) behaves, letting developers deploy and try out smart contracts and applications under realistic conditions. Test coins are usually handed out freely through “faucets.” When code has been proven on the testnet, it can be released to mainnet, where real value is at stake.

Why it matters

Testnets make it possible to find and fix bugs before real funds are involved, which is essential given that mainnet transactions and contract flaws are permanent. They are a standard, low-risk step in building anything on a blockchain.

Example

A developer deploys a new contract to a testnet first, then to mainnet once it works as intended.