Yes, it is possible to make money online using casino bonuses without risking your own cash. Online casinos offer various promotions such as sign-up bonuses or referral bonuses that can be used to place bets. By strategically betting on outcomes that cover all possibilities, like betting on both red and black in roulette, you can convert bonus money into real cash that can be withdrawn. However, it's important to read the fine print and understand the terms and conditions to avoid any risks.