Testnet

A Testnet (short for “test network”) is a parallel and public blockchain network that emulate the behavior of a mainnet, but where the tokens used have no economic value. These networks are specifically designed to allow for the development, testing and debugging of smart contracts, decentralized applications (dApps), wallets and Web3 tools without financial risks. Testnets reproduce the logic of consensus, block validation, gas consumption, execution of transactions and network events, but with modified parameters that allow obtaining free tokens from “faucets” and operating at no cost.

Each major blockchain network usually has one or more testnets: Ethereum has Sepolia, Holesky (formerly Goerli), Arbitrum has Arbitrum Sepolia, Polygon has Mumbai, among others. These testnets also allow you to simulate forks, network updates, protocol changes and experience new functionality before their final implementation in production.

On a technical level, launching a dApp on testnet involves deploying contracts in a secure environment, verifying that the logic works as expected, testing integrations with oracles, UIs and wallets, and auditing behavior in multiple scenarios. It is also a mandatory step prior to deployment on mainnet within professional environments and certification or legal compliance processes (for example, in regulated tokenizations). In short, testnets are infrastructure essential for quality, safety and efficiency of blockchain development.