Most testnet faucets require social login, GitHub authentication, or holding mainnet assets, creating friction for developers who just need a small amount of testnet tokens to get started.

OpenFaucet is open and permissionless. There are no accounts, no sign-ups, and no third-party dependencies. Anyone with a wallet address can claim testnet tokens by completing a proof-of-work challenge directly in their browser.

To prevent bots and abuse, each claim requires the browser to compute a set of valid Argon2 hashes, the same memory-hard algorithm used in modern password hashing. Because each proof requires substantial memory bandwidth and RAM, large-scale parallelisation is significantly more expensive and less efficient than traditional SHA-based mining.

Your browser mines proofs tied to your wallet address and the current session. Once enough are collected, the server independently verifies them before sending the transaction.

OpenFaucet is funded by top-ups. If you find it useful, consider sending a small amount of spare testnet tokens to the faucet wallet so others can continue to use it.