At casinos usually the minimum is 25 cents, even though they say 1 cent. It varies by machine. Just don't expect to win, play for fun, and free drinks.
Most slots offer a minimum bet of below $1 per spin, and the average maximum bet sits between $40 and $100. But there are plenty of online slots
The minimum bet was 10 cents per payline and the game had 25 paylines. The minimum bet was, to my way of thinking, $2.50. You could never bet
Low Volatility - Low volatility slots typically pay out small amounts more frequently, meaning your odds of winning on low volatility slots are higher. However,
If I'm playing a penny slot I usually bet 3 per line. So usually my bet is between 90 cents and 1.20, depending on the number of lines on the machine.
There is no minimum. It's not like you have to play a certain amount before a switch flips and the machine 'lets you win.