Have you ever wondered what the maximum level in Kingdom Hears 3 is? All your characters gain experience points that eventually leads them to leveling up, but when does it stop? As a matter of fact, the max level cap for Kingdom Hears 3 is level 99. Once you reach level 99, no further progress can be made, but you can still level up your Keyblade if you need to. The Keyblades can reach level 10, but it will take a good while to get them to that point.
Leveling up in Kingdom Hears 3 is primarily done by defeating enemies, and even tough the game is very long, it's unlikely that you will be able to hit level 99 before finishing the main story line. So be prepared to do some extra grinding if you want to hit that magic number!