Yes, African dwarf frogs can jump out of the tank. African dwarf frogs are excellent jumpers. When they jump in the wild, they likely just land back into the water. However, in captivity, they might accidentally jump out of their tank.
This can be very dangerous for the frogs. African dwarf frogs are very delicate, and landing on the floor from a relatively great height may injure them. Additionally, African dwarf frogs are fully aquatic and cannot survive for very long out of the water. If they jump out of their tank and aren’t immediately returned to the water, they might die.
In order to prevent your African dwarf frog from jumping out of the tank, you’ll need a tank cover.