There are no-deposit casinos, which will give you a bonus amount as soon as you sign up as a user.
But those are rare.
Most sites will require a small deposit before allowing you to access their offer. That deposit may be set to a minimum of $1, $5, $10, $20, or any amount in between.
The great thing about the online gambling industry is that it’s so competitive. The companies compete with each other to get the attention of their target audience. Since there are more and more players willing to bet with small amounts, it’s not unusual that the minimum bet requirements are getting lower.