The sproof testnet allows testing sproof for free. You can setup a free profile and discover the potentials of sproof at no cost. You can always switch to the mainnet for productive use. The testnet provides full access to all sproof features and uses the same interfaces and API as the sproof mainnet. Please note, however, that the sproof testnet uses the Ethereum testnet blockchain, may be subject to frequent changes and does not provide the quality and security guarantees of the mainnet. Never use the testnet for productive use. Developers can use the testnet for setting up and testing their processes before going productive on the mainnet.