What Is Testnet?

A testnet is an experimental network environment that allows developers to modify functionalities and track the performance of a network or DeFi application. To prevent potential mixups, developers test DeFi applications and new blockchains in an isolated network environment also known as a sandbox. The sandbox isolated environment is a more technical description for a testnet. Developers can fix bugs or errors in codes, and network failures that could potentially be exploited by malicious users on a testnet, blockchain. Developers also run multiple tests and reuse test files to ensure an accurate comparison between test runs. Blockchains like Ethereum provide standard testing tools, methodologies, and certifications to test complex networks and features. Development teams sometimes incentivize users to participate in large-scale testing to mimic real usage instances and expose potential lags prior to mainnet launches.


Testnets belong to the category of blockchain networks and they are an integral part of the onboarding process leading to the launch of a network. Transactions on the test network are different from the mainnet despite sharing similarities. To put it simply, a testnet mirrors activities that would otherwise happen on the mainnet. Launching a decentralized application on a testnet prevents irreversible mistakes that can flaw the entire development process when the application or network goes live.


Developers can run various development ideals in the secured testnet environment with minimal disruption. Given the technicality of problems developers intend to solve with new decentralized applications, they must test applications or networks multiple times by deploying prototypes on the testnet without disrupting mainnet transactions. These tests which occur in phases of fixes and patches include blockchain migration, security tests, load testing, blockchain migration, and disaster recovery.

Testnet ensures that applications or networks are efficient enough to serve end-users. It is the stage for rigorous evaluation and trials. After the testnet, code is made available as open-source for everyone to see and the website (front-end) goes live for users. Testnets on blockchains like Ethereum have unique IDs that are different from the mainnet. While the Ethereum mainnet ID is 1, the testnet IDs are 3, 4, and 42 for the Roopstein, Rinkebey, and Kovan testnet respectively.

Like mainnets, testnets have genesis blocks that are markedly distinct from the genesis block on the mainnet. The markers make tokens or coins generated on the testnet useless on the mainnet. It is also impossible to transfer testnet tokens to the mainnet and different addresses are used for transactions on either network. A good example of this distinction is available for review on the explorers of blockchains like Bitcoin. Note that contrary to popular examples, addresses can be the same as is the case with Ethereum.

Testnets also have fewer nodes and low transaction frequency. The mining difficulty, where it exists, is usually capped so that it doesn’t increase which keeps testnet tokens worthless. Remember that the mining difficulty determines the work done to solve or validate blocks on blockchains like Bitcoin and Ethereum which contributes to the current value of the tokens.

Important Points

  • A testnet is an experimental network environment for previewing and modifying the functionalities of a new network or Dapp.
  • The simulated background for testing functionalities on a testnet is an isolated sandbox environment.
  • Testnests are the battleground for monitoring, bug fixing, troubleshooting, evaluation, and patching before a launch on the mainnet.
  • Testnets allow applications and networks to be deployed without interfering with the mainnet.
  • Since blockchain transactions are irreversible, a testnet allows risk-free trial and error along with back and forth iteration, at no cost.
  • Testnets have unique IDs, fewer nodes, low transaction frequency, and limited block difficulty which keeps the tokens generated worthless.
  • Users of decentralized applications can also participate in testnet activities for potential rewards on the mainnet.

How Does the Testnet Work?

Testnets can be accessed by connecting a prebuilt application to the respective network using the network ID. Developers and users need a Web 3.0 enabled wallet to interact with the testnet. Transactions often start from a faucet where the user requests free tokens that can be used for transactions on the network. For developers, the mnemonic phrase of the wallet must be imported using a function in the Remix IDE. The command line must also be linked to the wallets with the test tokens. Ordinary users can simply proceed to the platform website to test the features by connecting the funded test wallets and sending tokens or testing borrowing features on DeFi applications. Unlike the mainnet, where each transaction attracts a fee and cost, the testnest only tries the network and exposes potential weaknesses which developers need to improve.

How Do You Use Testnet?

Testnet coins are crucial for transactions on the testnet. Developers and ordinary users who test networks or applications can get these coins by connecting to the testnet applicable to the blockchain. Some oracles like Chainlink also offer test tokens to users via faucets. A faucet is a website where you can input your wallet address and request tokens for free.

Node Approval

Nodes are computers that hold copies of the state of decentralized networks. As soon as transactions are validated by validator nodes on a blockchain, nodes update their copy of the ledger with these transactions. After updates are implemented on a testnet, some blockchains require the approval of nodes for the features to go live on the network.

Benefits of a Testnet Network

A testnet network is riskfree, enabling developers to explore possibilities until they reach a stable version of the project or application which can be implemented on the mainnet. It is an alternative that is as close as possible to the real network, but everything you do on the testnet has no consequence whatsoever, and the tokens are fake.