Can you put 2 female betta fish in a 1 gallon tank together without divider?

No, 2 female bettas should never be housed together in a 1 gallon tank without a divider. While female bettas are generally less aggressive than males, they can still be territorial and may fight with each other, especially in such as small, confined space.

A one gallon tank doesn’t provide enough space for two female bettas to establish their own territories, and they may constantly be harassing each other, leading to stress, injury or even death.

If you want to keep multiple bettas, you should provide each one with its own tank, or use a divided tank that provides each betta with its own separate space.