The BitMEX Testnet is a place where you can go to try out trading on BitMEX in a simulated sandbox environment that mirrors the real thing. We recommend the Testnet for new users who are unfamiliar with trading to practice placing, executing and cancelling orders of various order types and sizes.
Register for BitMEX Testnet here: https://testnet.bitmex.com/register
To trade on the Testnet you will need to deposit "Testnet Bitcoin". Testnet Bitcoin is a testing version of Bitcoin that has no monetary value. It is freely distributed from a number of faucets around the Internet. You can deposit and trade on your BitMEX Testnet account using these coins with no risk of actual monetary profit or loss.
The following faucets distribute Testnet Bitcoin: