As the Baby Sleep Site pointed out, the main function of rails on a toddler bed is to prevent falling out and keep your little one snug in his bed. ... The main reason rails are necessary is because toddlers are such wild sleepers, as What To Expect's website pointed out.

Is a toddler conversion kit necessary?

Essentially, the answer is “no”, you do not require a box spring with a convertible crib conversion. Sure, you could use one but you would end up creating a rather high bed for a toddler/child to climb into.

When can a child sleep without rails?

You can take the bed rails off when your child is 5 years old. However, after transitioning from the crib to a grown-up bed, it's not all kids who need bed rails at all. On the other hand, some type of toddler's beds has necessary side guards that should never be taken off.