To put it simply, for risk-free fun. Free online slot machines let you experience the fun of slot games without gambling any real money. Ultimately, this provides you with a risk-free environment to discover what type of slots you like best. After all, practice makes perfect, so getting familiar with how your favorite slots work gives you that all-important head start as and when you do play the real money variations. This is another reason we often recommend that you begin playing games in demo mode. You can also familiarize yourself with any bonus rounds or game mechanics.  Like in-person slot machines, their digital counterparts have changed tremendously over the year. A free-to-play online slot lets players see the latest developments without having to put money down.