What is a Devnet Airdrop / Faucet
Devnet SOL is essentially monopoly money. You can ask a CLI for some free SOL from a devnet faucet, or request it from a faucet on the faucet website, and it will be delivered to your account within a few seconds. Devnet, the devnet Solana cluster that the network runs on, runs the same production code that mainnet does. All the same validator computers, all the same programs, the same transaction flow. The only difference is that every token has deliberately been devalued, so you can use devnet to test your projects without paying fees in real money. In other words, the devnet SOL bills are printed with all of the proper instructions on how they should behave, but there is no store you can take them to spend the money at, and the bank always gives you more money for free when you ask for it.
How Airdrops Work Technically
You can request some free devnet SOL from the command line, by passing your public key as an argument to the solana airdrop command (the amount passed to the command is how much devnet SOL you would like to airdrop to your CLI- configured wallet). You can also request devnet SOL from faucet.solana.com, by pasting in your public key, though you will be rate limited to a few sol per day. This means that you can’t airdrop SOL to your public key indefinitely. If someone could, they would just write a bot and spam the network or try to resell devnet sol to other developers, charging for something that can only be produced for free. If your CLI is out of airdrops, RPC providers like Helius host multiple devnet faucets to get you more free devnet SOL. You can also move your devnet SOL between your own public keys like any other SOL in any way.
Note: While there is a Solana testnet cluster, testnet is meant for validators to test out new releases. Application developers use devnet. Additionally, there is no devnet airdrop available to you on mainnet-beta. It will give your public key a 400 response if you attempt to request SOL.
How Devnet Compares to Ethereum Testnets
In the Ethereum ecosystem, a typical way of getting testnet tokens is finding a working Ethereum testnet faucet and completing a captcha or proving you have a balance on Ethereum mainnet, but often these testnet ETH faucets are out of funds or have rate limits on how much one can receive. So developers spend time searching, and the faucets give you very little testnet ETH- for example, only 0.05 ETH on the Sepolia testnet. Since developers have to go through the effort to find the working faucet, and testnet Sepolia ETH has gained unofficial market value (and can actually be bought/sold on testnet markets), developers only receive a trickle of these testnet ETH. Devnet SOL has not gained such market value, and is so cheap that 2 devnet SOL can cover thousands of devnet test transactions. This means the first hour after getting started with Anchor is much different if you have used it from devnet Ethereum. In this example, the Ethereum developer had to spend all morning trying to get testnet Sepolia ETH just to get a devnet faucet to work and receive 0.05 ETH. Devnet SOL is always just a solana airdrop 1 away.
Let’s say you just deployed your first Anchor project and want to do more testing before deploying to mainnet-beta (where users can actually lose their money if you have a bug). You can just set your config to devnet, get a bunch of devnet SOL, and then deploy and do testing from there. You can even airdrop SOL to some random addresses with solana-keygen to simulate other users interacting with your project, and switch your Wallets (Phantom, Backpack, and others) to devnet in their respective settings so you can test your entire frontend. The total amount of time it takes to fund the testnet is less than a minute for free.
Why Devnet Matters
Devnet is a free place to make mistakes. A broken contract on Devnet just means you have to redeploy it, while on Mainnet, broken contracts cost users money and your reputation. Even large projects like Jupiter, Drift, and Metaplex use devnet to do most of their integration testing before moving into mainnet, as do smaller teams and individual devs. But be aware that devnet is intentionally volatile, and so do not assume devnet state or accounts are stable, especially if you were to want to build a demo using it and show that accounts still exist from a month ago. Additionally, be careful of scams involving devnet SOL. It might say 80,000 SOL if you look at it at mainnet prices, but that is still nothing because devnet SOL is worth zero on its own.
