Glossary
Testnet
16/04/2026
Testnet is a parallel blockchain network used for testing. It behaves identically to the main network (mainnet) but its coins have no monetary value, letting developers and users experiment safely before deploying to production.
Why testnets exist
- Developers test smart contracts and protocol upgrades without risking funds
- Miners test new hardware, software, or pool configurations
- Users can learn wallet software before using real money
- Researchers can probe edge cases and security properties
Notable testnets
- Bitcoin testnet3 — long-running Bitcoin testnet; tBTC has no value
- Ethereum Sepolia — current main Ethereum testnet for developers
- Ethereum Holesky — testnet focused on validator and staking operations
- Solana devnet / testnet — two tiers: devnet for app development, testnet for validator testing
Faucets
Because testnet coins have no value, they're distributed for free via faucets — web services that send small amounts to any address on request, usually rate-limited per user or per day.
Testnet coins are not real
Testnet coins cannot be bridged or swapped to mainnet coins. If anyone offers to buy or sell tBTC or Sepolia ETH, it's either a misunderstanding or a scam. Every few years, testnets reset or get replaced, wiping their history.
